P-loop containing Nucleoside Triphosphate Hydrolases; Members of the P-loop NTPase domain superfamily are characterized by a conserved nucleotide phosphate-binding motif, also referred to as the Walker A motif (GxxxxGK[S/T], where x is any residue), and the Walker B motif (hhhh[D/E], where h is a hydrophobic residue). The Walker A and B motifs bind the beta-gamma phosphate moiety of the bound nucleotide (typically ATP or GTP) and the Mg2+ cation, respectively. The P-loop NTPases are involved in diverse cellular functions, and they can be divided into two major structural classes: the KG (kinase-GTPase) class which includes Ras-like GTPases and its circularly permutated YlqF-like; and the ASCE (additional strand catalytic E) class which includes ATPase Binding Cassette (ABC), DExD/H-like helicases, 4Fe-4S iron sulfur cluster binding proteins of NifH family, RecA-like F1-ATPases, and ATPases Associated with a wide variety of Activities (AAA). Also included are a diverse set of nucleotide/nucleoside kinase families.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 927669114   5 RKKLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 52
Cdd:cd01870    1 RKKLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 48

Ras homology family A (RhoA)-like includes RhoA, RhoB and RhoC; The RhoA subfamily consists of RhoA, RhoB, and RhoC. RhoA promotes the formation of stress fibers and focal adhesions, regulating cell shape, attachment, and motility. RhoA can bind to multiple effector proteins, thereby triggering different downstream responses. In many cell types, RhoA mediates local assembly of the contractile ring, which is necessary for cytokinesis. RhoA is vital for muscle contraction; in vascular smooth muscle cells, RhoA plays a key role in cell contraction, differentiation, migration, and proliferation. RhoA activities appear to be elaborately regulated in a time- and space-dependent manner to control cytoskeletal changes. Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins. RhoA and RhoC are observed only in geranylgeranylated forms; however, RhoB can be present in palmitoylated, farnesylated, and geranylgeranylated forms. RhoA and RhoC are highly relevant for tumor progression and invasiveness; however, RhoB has recently been suggested to be a tumor suppressor. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 927669114   5 RKKLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 52
Cdd:cd01870    1 RKKLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 48

Ras family; Includes sub-families Ras, Rab, Rac, Ral, Ran, Rap Ypt1 and more. Shares P-loop motif with GTP_EFTU, arf and myosin_head. See pfam00009 pfam00025, pfam00063. As regards Rab GTPases, these are important regulators of vesicle formation, motility and fusion. They share a fold in common with all Ras GTPases: this is a six-stranded beta-sheet surrounded by five alpha-helices.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 927669114    7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTV-FENYVADIEVDGKQ 52
Cdd:pfam00071   1 KLVLVGDGGVGKSSLLIRFTQNKFPEEYIPTIgVDFYTKTIEVDGKT 47

Ras-like protein; Provisional

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 927669114   1 MAAIRKKLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVD 49
Cdd:PTZ00369   1 MASTEYKLVVVGGGGVGKSALTIQFIQNHFIDEYDPTIEDSYRKQCVID 49

Ras homology family A (RhoA)-like includes RhoA, RhoB and RhoC; The RhoA subfamily consists of RhoA, RhoB, and RhoC. RhoA promotes the formation of stress fibers and focal adhesions, regulating cell shape, attachment, and motility. RhoA can bind to multiple effector proteins, thereby triggering different downstream responses. In many cell types, RhoA mediates local assembly of the contractile ring, which is necessary for cytokinesis. RhoA is vital for muscle contraction; in vascular smooth muscle cells, RhoA plays a key role in cell contraction, differentiation, migration, and proliferation. RhoA activities appear to be elaborately regulated in a time- and space-dependent manner to control cytoskeletal changes. Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins. RhoA and RhoC are observed only in geranylgeranylated forms; however, RhoB can be present in palmitoylated, farnesylated, and geranylgeranylated forms. RhoA and RhoC are highly relevant for tumor progression and invasiveness; however, RhoB has recently been suggested to be a tumor suppressor. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 927669114   5 RKKLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 52
Cdd:cd01870    1 RKKLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 48

Ras homology family (Rho) of small guanosine triphosphatases (GTPases); Members of the Rho (Ras homology) family include RhoA, Cdc42, Rac, Rnd, Wrch1, RhoBTB, and Rop. There are 22 human Rho family members identified currently. These proteins are all involved in the reorganization of the actin cytoskeleton in response to external stimuli. They also have roles in cell transformation by Ras in cytokinesis, in focal adhesion formation and in the stimulation of stress-activated kinase. These various functions are controlled through distinct effector proteins and mediated through a GTP-binding/GTPase cycle involving three classes of regulating proteins: GAPs (GTPase-activating proteins), GEFs (guanine nucleotide exchange factors), and GDIs (guanine nucleotide dissociation inhibitors). Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins. Since crystal structures often lack C-terminal residues, this feature is not available for annotation in many of the CDs in the hierarchy.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 52
Cdd:cd00157    2 KIVVVGDGAVGKTCLLISYTTNKFPTEYVPTVFDNYSANVTVDGKQ 47

Ras homology family 2 (Rho2) of small guanosine triphosphatases (GTPases); Rho2 is a fungal GTPase that plays a role in cell morphogenesis, control of cell wall integrity, control of growth polarity, and maintenance of growth direction. Rho2 activates the protein kinase C homolog Pck2, and Pck2 controls Mok1, the major (1-3) alpha-D-glucan synthase. Together with Rho1 (RhoA), Rho2 regulates the construction of the cell wall. Unlike Rho1, Rho2 is not an essential protein, but its overexpression is lethal. Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for proper intracellular localization via membrane attachment. As with other Rho family GTPases, the GDP/GTP cycling is regulated by GEFs (guanine nucleotide exchange factors), GAPs (GTPase-activating proteins) and GDIs (guanine nucleotide dissociation inhibitors).

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 927669114   5 RKKLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGK 51
Cdd:cd04129    1 RRKLVIVGDGACGKTSLLYVFTLGEFPEEYHPTVFENYVTDCRVDGK 47

Rho family GTPase subfamily Rnd includes Rnd1/Rho6, Rnd2/Rho7, and Rnd3/RhoE/Rho8; The Rnd subfamily contains Rnd1/Rho6, Rnd2/Rho7, and Rnd3/RhoE/Rho8. These novel Rho family proteins have substantial structural differences compared to other Rho members, including N- and C-terminal extensions relative to other Rhos. Rnd3/RhoE is farnesylated at the C-terminal prenylation site, unlike most other Rho proteins that are geranylgeranylated. In addition, Rnd members are unable to hydrolyze GTP and are resistant to GAP activity. They are believed to exist only in the GTP-bound conformation, and are antagonists of RhoA activity. Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 927669114   5 RKKLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 52
Cdd:cd04131    1 RCKIVLVGDSQCGKTALLQVFAKDSFPENYVPTVFENYTASFEVDKQR 48

Ras homology family 3 (Rho3) of small guanosine triphosphatases (GTPases); Rho3 is a member of the Rho family found only in fungi. Rho3 is believed to regulate cell polarity by interacting with the diaphanous/formin family protein For3 to control both the actin cytoskeleton and microtubules. Rho3 is also believed to have a direct role in exocytosis that is independent of its role in regulating actin polarity. The function in exocytosis may be two-pronged: first, in the transport of post-Golgi vesicles from the mother cell to the bud, mediated by myosin (Myo2); second, in the docking and fusion of vesicles to the plasma membrane, mediated by an exocyst (Exo70) protein. Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 927669114   6 KKLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGK 51
Cdd:cd04134    1 RKVVVLGDGACGKTSLLNVFTRGYFPQVYEPTVFENYIHDIFVDGL 46

Ras homolog family, member G (RhoG) of small guanosine triphosphatases (GTPases); RhoG is a GTPase with high sequence similarity to members of the Rac subfamily, including the regions involved in effector recognition and binding. However, RhoG does not bind to known Rac1 and Cdc42 effectors, including proteins containing a Cdc42/Rac interacting binding (CRIB) motif. Instead, RhoG interacts directly with Elmo, an upstream regulator of Rac1, in a GTP-dependent manner and forms a ternary complex with Dock180 to induce activation of Rac1. The RhoG-Elmo-Dock180 pathway is required for activation of Rac1 and cell spreading mediated by integrin, as well as for neurite outgrowth induced by nerve growth factor. Thus RhoG activates Rac1 through Elmo and Dock180 to control cell morphology. RhoG has also been shown to play a role in caveolar trafficking and has a novel role in signaling the neutrophil respiratory burst stimulated by G protein-coupled receptor (GPCR) agonists. Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGK 51
Cdd:cd01875    5 KCVVVGDGAVGKTCLLICYTTNAFPKEYIPTVFDNYSAQTAVDGR 49

Ras-related C3 botulinum toxin substrate 1 (rho family, small GTP binding protein Rac1)-like consists of Rac1, Rac2 and Rac3; The Rac1-like subfamily consists of Rac1, Rac2, and Rac3 proteins, plus the splice variant Rac1b that contains a 19-residue insertion near switch II relative to Rac1. While Rac1 is ubiquitously expressed, Rac2 and Rac3 are largely restricted to hematopoietic and neural tissues respectively. Rac1 stimulates the formation of actin lamellipodia and membrane ruffles. It also plays a role in cell-matrix adhesion and cell anoikis. In intestinal epithelial cells, Rac1 is an important regulator of migration and mediates apoptosis. Rac1 is also essential for RhoA-regulated actin stress fiber and focal adhesion complex formation. In leukocytes, Rac1 and Rac2 have distinct roles in regulating cell morphology, migration, and invasion, but are not essential for macrophage migration or chemotaxis. Rac3 has biochemical properties that are closely related to Rac1, such as effector interaction, nucleotide binding, and hydrolysis; Rac2 has a slower nucleotide association and is more efficiently activated by the RacGEF Tiam1. Both Rac1 and Rac3 have been implicated in the regulation of cell migration and invasion in human metastatic breast cancer. Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGK 51
Cdd:cd01871    3 KCVVVGDGAVGKTCLLISYTTNAFPGEYIPTVFDNYSANVMVDGK 47

Rho-related protein from plants (Rop)-like; The Rop (Rho-related protein from plants) subfamily plays a role in diverse cellular processes, including cytoskeletal organization, pollen and vegetative cell growth, hormone responses, stress responses, and pathogen resistance. Rops are able to regulate several downstream pathways to amplify a specific signal by acting as master switches early in the signaling cascade. They transmit a variety of extracellular and intracellular signals. Rops are involved in establishing cell polarity in root-hair development, root-hair elongation, pollen-tube growth, cell-shape formation, responses to hormones such as abscisic acid (ABA) and auxin, responses to abiotic stresses such as oxygen deprivation, and disease resistance and disease susceptibility. An individual Rop can have a unique function or an overlapping function shared with other Rop proteins; in addition, a given Rop-regulated function can be controlled by one or multiple Rop proteins. For example, Rop1, Rop3, and Rop5 are all involved in pollen-tube growth; Rop2 plays a role in response to low-oxygen environments, cell-morphology, and root-hair development; root-hair development is also regulated by Rop4 and Rop6; Rop6 is also responsible for ABA response, and ABA response is also regulated by Rop10. Plants retain some of the regulatory mechanisms that are shared by other members of the Rho family, but have also developed a number of unique modes for regulating Rops. Unique RhoGEFs have been identified that are exclusively active toward Rop proteins, such as those containing the domain PRONE (plant-specific Rop nucleotide exchanger). Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDG 50
Cdd:cd04133    3 KCVTVGDGAVGKTCMLISYTSNTFPTDYVPTVFDNFSANVVVDG 46

small GTP-binding protein domain; Proteins with a small GTP-binding domain recognized by this model include Ras, RhoA, Rab11, translation elongation factor G, translation initiation factor IF-2, tetratcycline resistance protein TetM, CDC42, Era, ADP-ribosylation factors, tdhF, and many others. In some proteins the domain occurs more than once.This model recognizes a large number of small GTP-binding proteins and related domains in larger proteins. Note that the alpha chains of heterotrimeric G proteins are larger proteins in which the NKXD motif is separated from the GxxxxGK[ST] motif (P-loop) by a long insert and are not easily detected by this model. [Unknown function, General]

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 927669114    5 RKKLVIVGDGACGKTCLLIVFSKDQ-FPEVYVPTVFENYVAD-IEVDGKQKT 54
Cdd:TIGR00231   1 DIKIVIVGHPNVGKSTLLNSLLGNKgSITEYYPGTTRNYVTTvIEEDGKTYK 52

Ras-related in brain (Rab) family of small guanosine triphosphatases (GTPases); Rab GTPases form the largest family within the Ras superfamily. There are at least 60 Rab genes in the human genome, and a number of Rab GTPases are conserved from yeast to humans. Rab GTPases are small, monomeric proteins that function as molecular switches to regulate vesicle trafficking pathways. The different Rab GTPases are localized to the cytosolic face of specific intracellular membranes, where they regulate distinct steps in membrane traffic pathways. In the GTP-bound form, Rab GTPases recruit specific sets of effector proteins onto membranes. Through their effectors, Rab GTPases regulate vesicle formation, actin- and tubulin-dependent vesicle movement, and membrane fusion. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which mask C-terminal lipid binding and promote cytosolic localization. While most unicellular organisms possess 5-20 Rab members, several have been found to possess 60 or more Rabs; for many of these Rab isoforms, homologous proteins are not found in other organisms. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Since crystal structures often lack C-terminal residues, the lipid modification site is not available for annotation in many of the CDs in the hierarchy, but is included where possible.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVA-DIEVDGKQ 52
Cdd:cd00154    2 KIVLIGDSGVGKTSLLLRFVDNKFSENYKSTIGVDFKSkTIEVDGKK 48

Small GTPase of the Ras superfamily; ill-defined subfamily; SMART predicts Ras-like small GTPases of the ARF, RAB, RAN, RAS, and SAR subfamilies. Others that could not be classified in this way are predicted to be members of the small GTPase superfamily without predictions of the subfamily.

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*.
gi 927669114     7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 52
Cdd:smart00010   4 KLVVLGGGGVGKSALTIQFVQGHFVDEYDPTIEDSYRKQIEIDGEV 49

Rab subfamily of small GTPases; Rab GTPases are implicated in vesicle trafficking.

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*..
gi 927669114     7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTV-FENYVADIEVDGKQ 52
Cdd:smart00175   2 KIILIGDSGVGKSSLLSRFTDGKFSEQYKSTIgVDFKTKTIEVDGKR 48

Rab GTPase families 8, 10, 13 (Rab8, Rab10, Rab13); Rab8/Sec4/Ypt2 are known or suspected to be involved in post-Golgi transport to the plasma membrane. It is likely that these Rabs have functions that are specific to the mammalian lineage and have no orthologs in plants. Rab8 modulates polarized membrane transport through reorganization of actin and microtubules, induces the formation of new surface extensions, and has an important role in directed membrane transport to cell surfaces. The Ypt2 gene of the fission yeast Schizosaccharomyces pombe encodes a member of the Ypt/Rab family of small GTP-binding proteins, related in sequence to Sec4p of Saccharomyces cerevisiae but closer to mammalian Rab8. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTV---FEnyVADIEVDGK 51
Cdd:cd01867    5 KLLLIGDSGVGKSCLLLRFSEDSFNPSFISTIgidFK--IRTIELDGK 50

Ras GTPase family containing H-Ras,N-Ras and K-Ras4A/4B; H-Ras/N-Ras/K-Ras subfamily. H-Ras, N-Ras, and K-Ras4A/4B are the prototypical members of the Ras family. These isoforms generate distinct signal outputs despite interacting with a common set of activators and effectors, and are strongly associated with oncogenic progression in tumor initiation. Mutated versions of Ras that are insensitive to GAP stimulation (and are therefore constitutively active) are found in a significant fraction of human cancers. Many Ras guanine nucleotide exchange factors (GEFs) have been identified. They are sequestered in the cytosol until activation by growth factors triggers recruitment to the plasma membrane or Golgi, where the GEF colocalizes with Ras. Active (GTP-bound) Ras interacts with several effector proteins that stimulate a variety of diverse cytoplasmic signaling activities. Some are known to positively mediate the oncogenic properties of Ras, including Raf, phosphatidylinositol 3-kinase (PI3K), RalGEFs, and Tiam1. Others are proposed to play negative regulatory roles in oncogenesis, including RASSF and NORE/MST1. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDG 50
Cdd:cd04138    3 KLVVVGAGGVGKSALTIQLIQNHFVDEYDPTIEDSYRKQVVIDG 46

Rab GTPase family 1 includes the yeast homolog Ypt1; Rab1/Ypt1 subfamily. Rab1 is found in every eukaryote and is a key regulatory component for the transport of vesicles from the ER to the Golgi apparatus. Studies on mutations of Ypt1, the yeast homolog of Rab1, showed that this protein is necessary for the budding of vesicles of the ER as well as for their transport to, and fusion with, the Golgi apparatus. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENY-VADIEVDGK 51
Cdd:cd01869    4 KLLLIGDSGVGKSCLLLRFADDTYTESYISTIGVDFkIRTIELDGK 49

Rap1 family GTPase consists of Rap1a and Rap1b isoforms; The Rap1 subgroup is part of the Rap subfamily of the Ras family. It can be further divided into the Rap1a and Rap1b isoforms. In humans, Rap1a and Rap1b share 95% sequence homology, but are products of two different genes located on chromosomes 1 and 12, respectively. Rap1a is sometimes called smg p21 or Krev1 in the older literature. Rap1 proteins are believed to perform different cellular functions, depending on the isoform, its subcellular localization, and the effector proteins it binds. For example, in rat salivary gland, neutrophils, and platelets, Rap1 localizes to secretory granules and is believed to regulate exocytosis or the formation of secretory granules. Rap1 has also been shown to localize in the Golgi of rat fibroblasts, zymogen granules, plasma membrane, and the microsomal membrane of pancreatic acini, as well as in the endocytic compartment of skeletal muscle cells and fibroblasts. High expression of Rap1 has been observed in the nucleus of human oropharyngeal squamous cell carcinomas (SCCs) and cell lines; interestingly, in the SCCs, the active GTP-bound form localized to the nucleus, while the inactive GDP-bound form localized to the cytoplasm. Rap1 plays a role in phagocytosis by controlling the binding of adhesion receptors (typically integrins) to their ligands. In yeast, Rap1 has been implicated in multiple functions, including activation and silencing of transcription and maintenance of telomeres. Rap1a, which is stimulated by T-cell receptor (TCR) activation, is a positive regulator of T cells by directing integrin activation and augmenting lymphocyte responses. In murine hippocampal neurons, Rap1b determines which neurite will become the axon and directs the recruitment of Cdc42, which is required for formation of dendrites and axons. In murine platelets, Rap1b is required for normal homeostasis in vivo and is involved in integrin activation. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 52
Cdd:cd04175    3 KLVVLGSGGVGKSALTVQFVQGIFVEKYDPTIEDSYRKQVEVDGQQ 48

Rap2 family GTPase consists of Rap2a, Rap2b, and Rap2c; The Rap2 subgroup is part of the Rap subfamily of the Ras family. It consists of Rap2a, Rap2b, and Rap2c. Both isoform 3 of the human mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) and Traf2- and Nck-interacting kinase (TNIK) are putative effectors of Rap2 in mediating the activation of c-Jun N-terminal kinase (JNK) to regulate the actin cytoskeleton. In human platelets, Rap2 was shown to interact with the cytoskeleton by binding the actin filaments. In embryonic Xenopus development, Rap2 is necessary for the Wnt/beta-catenin signaling pathway. The Rap2 interacting protein 9 (RPIP9) is highly expressed in human breast carcinomas and correlates with a poor prognosis, suggesting a role for Rap2 in breast cancer oncogenesis. Rap2b, but not Rap2a, Rap2c, Rap1a, or Rap1b, is expressed in human red blood cells, where it is believed to be involved in vesiculation. A number of additional effector proteins for Rap2 have been identified, including the RalGEFs RalGDS, RGL, and Rlf, which also interact with Rap1 and Ras. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDG 50
Cdd:cd04176    3 KVVVLGSGGVGKSALTVQFVSGTFIEKYDPTIEDFYRKEIEVDS 46

Ral (Ras-like) family containing highly homologous RalA and RalB; The Ral (Ras-like) subfamily consists of the highly homologous RalA and RalB. Ral proteins are believed to play a crucial role in tumorigenesis, metastasis, endocytosis, and actin cytoskeleton dynamics. Despite their high sequence similarity (>80% sequence identity), nonoverlapping and opposing functions have been assigned to RalA and RalBs in tumor migration. In human bladder and prostate cancer cells, RalB promotes migration while RalA inhibits it. A Ral-specific set of GEFs has been identified that are activated by Ras binding. This RalGEF activity is enhanced by Ras binding to another of its target proteins, phosphatidylinositol 3-kinase (PI3K). Ral effectors include RLIP76/RalBP1, a Rac/cdc42 GAP, and the exocyst (Sec6/8) complex, a heterooctomeric protein complex that is involved in tethering vesicles to specific sites on the plasma membrane prior to exocytosis. In rat kidney cells, RalB is required for functional assembly of the exocyst and for localizing the exocyst to the leading edge of migrating cells. In human cancer cells, RalA is required to support anchorage-independent proliferation and RalB is required to suppress apoptosis. RalA has been shown to localize to the plasma membrane while RalB is localized to the intracellular vesicles. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVADIEVDGKQ 52
Cdd:cd04139    2 KVIMVGSGGVGKSALTLQFMYDEFVEDYEPTKADSYRKKVVLDGEE 47

Rab GTPase family 2 (Rab2); Rab2 is localized on cis-Golgi membranes and interacts with Golgi matrix proteins. Rab2 is also implicated in the maturation of vesicular tubular clusters (VTCs), which are microtubule-associated intermediates in transport between the ER and Golgi apparatus. In plants, Rab2 regulates vesicle trafficking between the ER and the Golgi bodies and is important to pollen tube growth. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVAD-IEVDGKQ 52
Cdd:cd01866    6 KYIIIGDTGVGKSCLLLQFTDKRFQPVHDLTIGVEFGARmITIDGKQ 52

Rab GTPase family 28 (Rab28); Rab28 subfamily. First identified in maize, Rab28 has been shown to be a late embryogenesis-abundant (Lea) protein that is regulated by the plant hormone abcisic acid (ABA). In Arabidopsis, Rab28 is expressed during embryo development and is generally restricted to provascular tissues in mature embryos. Unlike maize Rab28, it is not ABA-inducible. Characterization of the human Rab28 homolog revealed two isoforms, which differ by a 95-base pair insertion, producing an alternative sequence for the 30 amino acids at the C-terminus. The two human isoforms are presumably the result of alternative splicing. Since they differ at the C-terminus but not in the GTP-binding region, they are predicted to be targeted to different cellular locations. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                         10        20        30
                 ....*....|....*....|....*....|..
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTV 38
Cdd:cd04109    2 KIVVLGDGASGKTSLIRRFAQEGFGKSYKQTI 33

Rab GTPase family 18 (Rab18); Rab18 subfamily. Mammalian Rab18 is implicated in endocytic transport and is expressed most highly in polarized epithelial cells. However, trypanosomal Rab, TbRAB18, is upregulated in the BSF (Blood Stream Form) stage and localized predominantly to elements of the Golgi complex. In human and mouse cells, Rab18 has been identified in lipid droplets, organelles that store neutral lipids. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*.
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENY-VADIEVDGK 51
Cdd:cd01863    2 KILLIGDSGVGKSSLLLRFTDDTFDEDLSSTIGVDFkVKTVTVDGK 47

GTPase SAR1 family domain [General function prediction only];

                         10        20        30
                 ....*....|....*....|....*....|....*.
gi 927669114   4 IRKKLVIVGDGACGKTCLLIVFSKDQF-PEVYVPTV 38
Cdd:COG1100    2 GEKKIVVVGTGGVGKTSLVNRLVGDIFsLEKYLSTN 37

Rab GTPase family 7 (Rab7); Rab7 subfamily. Rab7 is a small Rab GTPase that regulates vesicular traffic from early to late endosomal stages of the endocytic pathway. The yeast Ypt7 and mammalian Rab7 are both involved in transport to the vacuole/lysosome, whereas Ypt7 is also required for homotypic vacuole fusion. Mammalian Rab7 is an essential participant in the autophagic pathway for sequestration and targeting of cytoplasmic components to the lytic compartment. Mammalian Rab7 is also proposed to function as a tumor suppressor. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENYVA-DIEVDGKQKTSQ 56
Cdd:cd01862    2 KVIILGDSGVGKTSLMNQYVNKKFSNQYKATIGADFLTkEVTVDDRLVTLQ 52

Rab GTPase family 39 (Rab39); Found in eukaryotes, Rab39 is mainly found in epithelial cell lines, but is distributed widely in various human tissues and cell lines. It is believed to be a novel Rab protein involved in regulating Golgi-associated vesicular transport during cellular endocytosis. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTV---FENYVADIEvDGKQ 52
Cdd:cd04111    4 RLIVIGDSTVGKSSLLKRFTEGRFAEVSDPTVgvdFFSRLIEIE-PGVR 51

Rat sarcoma (Ras)-like superfamily of small guanosine triphosphatases (GTPases); Ras-like GTPase superfamily. The Ras-like superfamily of small GTPases consists of several families with an extremely high degree of structural and functional similarity. The Ras superfamily is divided into at least four families in eukaryotes: the Ras, Rho, Rab, and Sar1/Arf families. This superfamily also includes proteins like the GTP translation factors, Era-like GTPases, and G-alpha chain of the heterotrimeric G proteins. Members of the Ras superfamily regulate a wide variety of cellular functions: the Ras family regulates gene expression, the Rho family regulates cytoskeletal reorganization and gene expression, the Rab and Sar1/Arf families regulate vesicle trafficking, and the Ran family regulates nucleocytoplasmic transport and microtubule organization. The GTP translation factor family regulates initiation, elongation, termination, and release in translation, and the Era-like GTPase family regulates cell division, sporulation, and DNA replication. Members of the Ras superfamily are identified by the GTP binding site, which is made up of five characteristic sequence motifs, and the switch I and switch II regions.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 927669114   9 VIVGDGACGKTCLLIVFSKDQFPEV---YVPTVFENYVADIEVDGKQK 53
Cdd:cd00882    1 VVVGRGGVGKSSLLNALLGGEVGEVsdvPGTTRDPDVYVKELDKGKVK 48

A Ras homolog member I (ARHI); ARHI (A Ras homolog member I) is a member of the Ras family with several unique structural and functional properties. ARHI is expressed in normal human ovarian and breast tissue, but its expression is decreased or eliminated in breast and ovarian cancer. ARHI contains an N-terminal extension of 34 residues (human) that is required to retain its tumor suppressive activity. Unlike most other Ras family members, ARHI is maintained in the constitutively active (GTP-bound) state in resting cells and has modest GTPase activity. ARHI inhibits STAT3 (signal transducers and activators of transcription 3), a latent transcription factor whose abnormal activation plays a critical role in oncogenesis. Most Ras proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Ras proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

                         10        20        30
                 ....*....|....*....|....*....|....*.
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTVFENY 42
Cdd:cd04140    3 RVVVFGAGGVGKSSLVLRFVKGTFRESYIPTIEDTY 38

GTP-binding nuclear protein Ran; Provisional

                         10        20        30
                 ....*....|....*....|....*....|..
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTV 38
Cdd:PTZ00132  11 KLILVGDGGVGKTTFVKRHLTGEFEKKYIPTL 42

GTP-binding nuclear protein Ran; Provisional

                         10        20        30
                 ....*....|....*....|....*....|..
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPEVYVPTV 38
Cdd:PLN03071  15 KLVIVGDGGTGKTTFVKRHLTGEFEKKYEPTI 46

Rab GTPase families 34 (Rab34) and 36 (Rab36); Rab34/Rab36 subfamily. Rab34, found primarily in the Golgi, interacts with its effector, Rab-interacting lysosomal protein (RILP). This enables its participation in microtubular dynenin-dynactin-mediated repositioning of lysosomes from the cell periphery to the Golgi. A Rab34 (Rah) isoform that lacks the consensus GTP-binding region has been identified in mice. This isoform is associated with membrane ruffles and promotes macropinosome formation. Rab36 has been mapped to human chromosome 22q11.2, a region that is homozygously deleted in malignant rhabdoid tumors (MRTs). However, experimental assessments do not implicate Rab36 as a tumor suppressor that would enable tumor formation through a loss-of-function mechanism. GTPase activating proteins (GAPs) interact with GTP-bound Rab and accelerate the hydrolysis of GTP to GDP. Guanine nucleotide exchange factors (GEFs) interact with GDP-bound Rabs to promote the formation of the GTP-bound state. Rabs are further regulated by guanine nucleotide dissociation inhibitors (GDIs), which facilitate Rab recycling by masking C-terminal lipid binding and promoting cytosolic localization. Most Rab GTPases contain a lipid modification site at the C-terminus, with sequence motifs CC, CXC, or CCX. Lipid binding is essential for membrane attachment, a key feature of most Rab proteins.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|...
gi 927669114   7 KLVIVGDGACGKTCLLIVFSKDQFPevyvptvfENYVADIEVD 49
Cdd:cd04108    2 KVIVVGDLSVGKTCLINRFCKDVFD--------KNYKATIGVD 36