C-type lectin (CTL)/C-type lectin-like (CTLD) domain; CLECT: C-type lectin (CTL)/C-type lectin-like (CTLD) domain; protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. This group is chiefly comprised of eukaryotic CTLDs, but contains some, as yet functionally uncharacterized, bacterial CTLDs. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces, including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. For example: mannose-binding lectin and lung surfactant proteins A and D bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, and apoptotic cells) and mediate functions associated with killing and phagocytosis; P (platlet)-, E (endothelial)-, and L (leukocyte)- selectins (sels) mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. Several CTLDs bind to protein ligands, and only some of these binding interactions are Ca2+-dependent; including the CTLDs of Coagulation Factors IX/X (IX/X) and Von Willebrand Factor (VWF) binding proteins, and natural killer cell receptors. C-type lectins, such as lithostathine, and some type II antifreeze glycoproteins function in a Ca2+-independent manner to bind inorganic surfaces. Many proteins in this group contain a single CTLD; these CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers, from which ligand-binding sites project in different orientations. Various vertebrate type 1 transmembrane proteins including macrophage mannose receptor, endo180, phospholipase A2 receptor, and dendritic and epithelial cell receptor (DEC205) have extracellular domains containing 8 or more CTLDs; these CTLDs remain in the parent model. In some members (IX/X and VWF binding proteins), a loop extends to the adjoining domain to form a loop-swapped dimer. A similar conformation is seen in the macrophage mannose receptor CRD4's putative non-sugar bound form of the domain in the acid environment of the endosome. Lineage specific expansions of CTLDs have occurred in several animal lineages including Drosophila melanogaster and Caenorhabditis elegans; these CTLDs also remain in the parent model.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1433354043 132 KKYFVSSVKKMSLDRVKALCSEFQGSVATPRNAEENSAIQKVAKDI---AYLGITDVRVEGSFEDLTGNRVRYTNWNDGE 208
Cdd:cd03591     1 EKIFVTNGEEKNFDDAQKLCSEAGGTLAMPRNAAENAAIASYVKKGntyAFIGITDLETEGQFVYLDGGPLTYTNWKPGE 80

                          90       100       110
                  ....*....|....*....|....*....|....
gi 1433354043 209 PNNTGDGEDCVVILGNGKWNDVPCSDSFLAICEF 242
Cdd:cd03591    81 PNNAGGGEDCVEMYTSGKWNDVACNLTRLFVCEF 114

C-type lectin-like domain (CTLD) of the type found in human collectins including lung surfactant proteins A and D, mannose- or mannan binding lectin (MBL), and CL-L1 (collectin liver 1); CLECT_collectin_like: C-type lectin-like domain (CTLD) of the type found in human collectins including lung surfactant proteins A and D, mannose- or mannan binding lectin (MBL), and CL-L1 (collectin liver 1). CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. The CTLDs of these collectins bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, or apoptotic cells) and mediate functions associated with killing and phagocytosis. MBPs recognize high mannose oligosaccharides in a calcium dependent manner, bind to a broad range of pathogens, and trigger cell killing by activating the complement pathway. MBP also acts directly as an opsonin. SP-A and SP-D in addition to functioning as host defense components, are components of pulmonary surfactant which play a role in surfactant homeostasis. Pulmonary surfactant is a phospholipid-protein complex which reduces the surface tension within the lungs. SP-A binds the major surfactant lipid: dipalmitoylphosphatidylcholine (DPPC). SP-D binds two minor components of surfactant that contain sugar moieties: glucosylceramide and phosphatidylinositol (PI). MBP and SP-A, -D monomers are homotrimers with an N-terminal collagen region and three CTLDs. Multiple homotrimeric units associate to form supramolecular complexes. MBL deficiency results in an increased susceptibility to a large number of different infections and to inflammatory disease, such as rheumatoid arthritis.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1433354043 132 KKYFVSSVKKMSLDRVKALCSEFQGSVATPRNAEENSAIQKVAKDI---AYLGITDVRVEGSFEDLTGNRVRYTNWNDGE 208
Cdd:cd03591     1 EKIFVTNGEEKNFDDAQKLCSEAGGTLAMPRNAAENAAIASYVKKGntyAFIGITDLETEGQFVYLDGGPLTYTNWKPGE 80

                          90       100       110
                  ....*....|....*....|....*....|....
gi 1433354043 209 PNNTGDGEDCVVILGNGKWNDVPCSDSFLAICEF 242
Cdd:cd03591    81 PNNAGGGEDCVEMYTSGKWNDVACNLTRLFVCEF 114

C-type lectin (CTL) or carbohydrate-recognition domain (CRD); Many of these domains function as calcium-dependent carbohydrate binding modules.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1433354043  120 NWVLFSlsekvGKKYFVSSvKKMSLDRVKALCSEFQGSVATPRNAEENSAIQKVAK-----DIAYLGITDVRVEGSFE-- 192
Cdd:smart00034   4 GWISYG-----GKCYKFST-EKKTWEDAQAFCQSLGGHLASIHSEAENDFVASLLKnsgssDYYWIGLSDPDSNGSWQws 77

                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|
gi 1433354043  193 DLTGNrVRYTNWNDGEPNNTgdGEDCVVI-LGNGKWNDVPCSDSFLAICE 241
Cdd:smart00034  78 DGSGP-VSYSNWAPGEPNNS--SGDCVVLsTSGGKWNDVSCTSKLPFVCE 124

LPXTG-anchored collagen-like adhesin Scl2/SclB; SclB (or Scl2 - streptococcal collagen-like protein 2) is an LPXTG-anchored surface-anchored adhesin with a variable-length region of triple helix-forming collagen-like Gly-Xaa-Xaa repeats.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1433354043  17 YAETLTEGVQNSCPVVTCSSPGLNGFPGKDGRDGAKGEKGEPG----------QGLRGL------QGPPGKVGPTGPPGN 80
Cdd:NF038329  102 YLEELDEGLQQLKGDGEKGEPGPAGPAGPAGEQGPRGDRGETGpagpagppgpQGERGEkgpagpQGEAGPQGPAGKDGE 181

                          90
                  ....*....|....*...
gi 1433354043  81 PGLKGAVGPKGDRGDRAE 98
Cdd:NF038329  182 AGAKGPAGEKGPQGPRGE 199

LPXTG-anchored collagen-like adhesin Scl2/SclB; SclB (or Scl2 - streptococcal collagen-like protein 2) is an LPXTG-anchored surface-anchored adhesin with a variable-length region of triple helix-forming collagen-like Gly-Xaa-Xaa repeats.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1433354043  38 GLNGFPGKDGRDGAKGEKGEPGQglRGLQGPPGKVGPTGPPGNPGLKGAVGPK 90
Cdd:NF038329  293 GKDGLPGKDGKDGQNGKDGLPGK--DGKDGQPGKDGLPGKDGKDGQPGKPAPK 343

C-type lectin-like domain (CTLD) of the type found in human collectins including lung surfactant proteins A and D, mannose- or mannan binding lectin (MBL), and CL-L1 (collectin liver 1); CLECT_collectin_like: C-type lectin-like domain (CTLD) of the type found in human collectins including lung surfactant proteins A and D, mannose- or mannan binding lectin (MBL), and CL-L1 (collectin liver 1). CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. The CTLDs of these collectins bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, or apoptotic cells) and mediate functions associated with killing and phagocytosis. MBPs recognize high mannose oligosaccharides in a calcium dependent manner, bind to a broad range of pathogens, and trigger cell killing by activating the complement pathway. MBP also acts directly as an opsonin. SP-A and SP-D in addition to functioning as host defense components, are components of pulmonary surfactant which play a role in surfactant homeostasis. Pulmonary surfactant is a phospholipid-protein complex which reduces the surface tension within the lungs. SP-A binds the major surfactant lipid: dipalmitoylphosphatidylcholine (DPPC). SP-D binds two minor components of surfactant that contain sugar moieties: glucosylceramide and phosphatidylinositol (PI). MBP and SP-A, -D monomers are homotrimers with an N-terminal collagen region and three CTLDs. Multiple homotrimeric units associate to form supramolecular complexes. MBL deficiency results in an increased susceptibility to a large number of different infections and to inflammatory disease, such as rheumatoid arthritis.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1433354043 132 KKYFVSSVKKMSLDRVKALCSEFQGSVATPRNAEENSAIQKVAKDI---AYLGITDVRVEGSFEDLTGNRVRYTNWNDGE 208
Cdd:cd03591     1 EKIFVTNGEEKNFDDAQKLCSEAGGTLAMPRNAAENAAIASYVKKGntyAFIGITDLETEGQFVYLDGGPLTYTNWKPGE 80

                          90       100       110
                  ....*....|....*....|....*....|....
gi 1433354043 209 PNNTGDGEDCVVILGNGKWNDVPCSDSFLAICEF 242
Cdd:cd03591    81 PNNAGGGEDCVEMYTSGKWNDVACNLTRLFVCEF 114

C-type lectin (CTL) or carbohydrate-recognition domain (CRD); Many of these domains function as calcium-dependent carbohydrate binding modules.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1433354043  120 NWVLFSlsekvGKKYFVSSvKKMSLDRVKALCSEFQGSVATPRNAEENSAIQKVAK-----DIAYLGITDVRVEGSFE-- 192
Cdd:smart00034   4 GWISYG-----GKCYKFST-EKKTWEDAQAFCQSLGGHLASIHSEAENDFVASLLKnsgssDYYWIGLSDPDSNGSWQws 77

                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|
gi 1433354043  193 DLTGNrVRYTNWNDGEPNNTgdGEDCVVI-LGNGKWNDVPCSDSFLAICE 241
Cdd:smart00034  78 DGSGP-VSYSNWAPGEPNNS--SGDCVVLsTSGGKWNDVSCTSKLPFVCE 124

C-type lectin-like domain (CTLD) of the type found in human dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and the related receptor, DC-SIGN receptor (DC-SIGNR); CLECT_DC-SIGN_like: C-type lectin-like domain (CTLD) of the type found in human dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and the related receptor, DC-SIGN receptor (DC-SIGNR). This group also contains proteins similar to hepatic asialoglycoprotein receptor (ASGP-R) and langerin in human. These proteins are type II membrane proteins with a CTLD ectodomain. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. DC-SIGN is thought to mediate the initial contact between dendritic cells and resting T cells, and may also mediate the rolling of DCs on epithelium. DC-SIGN and DC-SIGNR bind to oligosaccharides present on human tissues, as well as, on pathogens including parasites, bacteria, and viruses. DC-SIGN and DC-SIGNR bind to HIV enhancing viral infection of T cells. DC-SIGN and DC-SIGNR are homotetrameric, and contain four CTLDs stabilized by a coiled coil of alpha helices. The hepatic ASGP-R is an endocytic recycling receptor which binds and internalizes desialylated glycoproteins having a terminal galactose or N-acetylgalactosamine residues on their N-linked carbohydrate chains, via the clathrin-coated pit mediated endocytic pathway, and delivers them to lysosomes for degradation. It has been proposed that glycoproteins bearing terminal Sia (sialic acid) alpha2, 6GalNAc and Sia alpha2, 6Gal are endogenous ligands for ASGP-R and that ASGP-R participates in regulating the relative concentration of serum glycoproteins bearing alpha 2,6-linked Sia. The human ASGP-R is a hetero-oligomer composed of two subunits, both of which are found within this group. Langerin is expressed in a subset of dendritic leukocytes, the Langerhans cells (LC). Langerin induces the formation of Birbeck Granules (BGs) and associates with these BGs following internalization. Langerin binds, in a calcium-dependent manner, to glyco-conjugates containing mannose and related sugars mediating their uptake and degradation. Langerin molecules oligomerize as trimers with three CTLDs held together by a coiled-coil of alpha helices.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1433354043 120 NWVLFSlsekvGKKYFVSSVKKmSLDRVKALCSEFQGSVATPRNAEENSAIQKVA--KDIAYLGITDVRVEGSFE--DLT 195
Cdd:cd03590     4 NWKSFQ-----SSCYFFSTEKK-SWEESRQFCEDMGAHLVIINSQEEQEFISKILsgNRSYWIGLSDEETEGEWKwvDGT 77

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 1433354043 196 GNRVRYTNWNDGEPNN-TGDGEDCVVILGN-GKWNDVPCSDSFLAICE 241
Cdd:cd03590    78 PLNSSKTFWHPGEPNNwGGGGEDCAELVYDsGGWNDVPCNLEYRWICE 125

C-type lectin-like domain (CTLD) of the type found in the type 1 transmembrane proteins: P(platlet)-, E(endothelial)-, and L(leukocyte)- selectins (sels); CLECT_selectins_like: C-type lectin-like domain (CTLD) of the type found in the type 1 transmembrane proteins: P(platlet)-, E(endothelial)-, and L(leukocyte)- selectins (sels). CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. P- E- and L-sels are cell adhesion receptors that mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. L- sel is expressed constitutively on most leukocytes. P-sel is stored in the Weibel-Palade bodies of endothelial cells and in the alpha granules of platlets. E- sels are present on endothelial cells. Following platelet and/or endothelial cell activation P- sel is rapidly translocated to the cell surface and E-sel expression is induced. The initial step in leukocyte migration involves interactions of selectins with fucosylated, sialylated, and sulfated carbohydrate moieties on target ligands displayed on glycoprotein scaffolds on endothelial cells and leucocytes. A major ligand of P- E- and L-sels is PSGL-1 (P-sel glycoprotein ligand). Interactions of E- and P- sels with tumor cells may promote extravasation of cancer cells. Regulation of L-sel and P-sel function includes proteolytic shedding of the most extracellular portion (containing the CTLD) from the cell surface. Increased levels of the soluble form of P-sel in the plasma have been found in a number of diseases including coronary disease and diabetes. E- and P- sel also play roles in the development of synovial inflammation in inflammatory arthritis. Platelet P-sel, but not endothelial P-sel, plays a role in the inflammatory response and neointimal formation after arterial injury. Selectins may also function as signal-transducing receptors.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1433354043 134 YFVSSvKKMSLDRVKALCSEFQGSVATPRNAEENSAIQKVAK----DIAYLGITDVRVEGSFEDLTGNRVRYTNWNDGEP 209
Cdd:cd03592     3 YHYST-EKMTFNEAVKYCKSRGTDLVAIQNAEENALLNGFALkynlGYYWIDGNDINNEGTWVDTDKKELEYKNWAPGEP 81

                          90       100       110
                  ....*....|....*....|....*....|....
gi 1433354043 210 NNTGdGEDCVV--ILGNGKWNDVPCSDSFLAICE 241
Cdd:cd03592    82 NNGR-NENCLEiyIKDNGKWNDEPCSKKKSAICY 114

A bacterial subgroup of the C-type lectin-like (CTLD) domain; a subgroup of bacterial protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins; CLECT_VCBS: A bacterial subgroup of the C-type lectin-like (CTLD) domain; a subgroup of bacterial protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces including CaCO3 and ice. Bacterial CTLDs within this group are functionally uncharacterized. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers from which ligand-binding sites project in different orientations. In some CTLDs a loop extends to the adjoining domain to form a loop-swapped dimer.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1433354043 134 YFVSSVKKMSLDRVKALCSEFQGSVATPRNAEENSAIQKVAKDIA--YLGITDVRVEGSFEDLTGNRVRYTNWNDGEP-N 210
Cdd:cd03603     2 FYKFVDGGMTWEAAQTLAESLGGHLVTINSAEENDWLLSNFGGYGasWIGASDAATEGTWKWSDGEESTYTNWGSGEPhN 81

                          90       100
                  ....*....|....*....|....*
gi 1433354043 211 NTGDGEDCVVI----LGNGKWNDVP 231
Cdd:cd03603    82 NGGGNEDYAAInhfpGISGKWNDLA 106

Collagen triple helix repeat (20 copies); Members of this family belong to the collagen superfamily. Collagens are generally extracellular structural proteins involved in formation of connective tissue structure. The alignment contains 20 copies of the G-X-Y repeat that forms a triple helix. The first position of the repeat is glycine, the second and third positions can be any residue but are frequently proline and hydroxy-proline. Collagens are post translationally modified by proline hydroxylase to form the hydroxy-proline residues. Defective hydroxylation is the cause of scurvy. Some members of the collagen superfamily are not involved in connective tissue structure but share the same triple helical structure. The family includes bacterial collagen-like triple-helix repeat proteins.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1433354043  36 SPGLNGFPGKDGRDGAKGEKGEPG-QGLRGLQGPPGKvgptgpPGNPGLKGAVGPKGDR 93
Cdd:pfam01391   5 PPGPPGPPGPPGPPGPPGPPGPPGpPGEPGPPGPPGP------PGPPGPPGAPGAPGPP 57

C-type lectin (CTL)/C-type lectin-like (CTLD) domain subgroup 1; a subgroup of protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins; CLECT_1: C-type lectin (CTL)/C-type lectin-like (CTLD) domain subgroup 1; a subgroup of protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers from which ligand-binding sites project in different orientations. In some CTLDs a loop extends to the adjoining domain to form a loop-swapped dimer.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1433354043 149 ALCSEFQGSVATPRNAEENSAIQKVAK---DIAYLGITDVRVEGSFEDltGNRVRYTNWNdgePNNTGDGEDCVVILGNG 225
Cdd:cd03602    17 QYCRENYTDLATVQNQEDNALLSNLSRvsnSAAWIGLYRDVDSWRWSD--GSESSFRNWN---TFQPFGQGDCATMYSSG 91

                          90
                  ....*....|....*
gi 1433354043 226 KWNDVPCSDSFLAIC 240
Cdd:cd03602    92 RWYAALCSALKPFIC 106

LPXTG-anchored collagen-like adhesin Scl2/SclB; SclB (or Scl2 - streptococcal collagen-like protein 2) is an LPXTG-anchored surface-anchored adhesin with a variable-length region of triple helix-forming collagen-like Gly-Xaa-Xaa repeats.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1433354043  38 GLNGFPGKDGRDGAKGEKGEPGQglRGLQGPPGKVGPTGPPGNPGLKGAVGPK 90
Cdd:NF038329  293 GKDGLPGKDGKDGQNGKDGLPGK--DGKDGQPGKDGLPGKDGKDGQPGKPAPK 343

C-type lectin-like domain (CTLD) of the type found in lectins TC14, TC14-2, TC14-3, and TC14-4 from the budding tunicate Polyandrocarpa misakiensis and PfG6 from the Acorn worm; CLECT_TC14_like: C-type lectin-like domain (CTLD) of the type found in lectins TC14, TC14-2, TC14-3, and TC14-4 from the budding tunicate Polyandrocarpa misakiensis and PfG6 from the Acorn worm. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. TC14 is homodimeric. The CTLD of TC14 binds D-galactose and D-fucose. TC14 is expressed constitutively by multipotent epithelial and mesenchymal cells and plays in role during budding, in inducing the aggregation of undifferentiated mesenchymal cells to give rise to epithelial forming tissue. TC14-2 and TC14-3 shows calcium-dependent galactose binding activity. TC14-3 is a cytostatic factor which blocks cell growth and dedifferentiation of the atrial epithelium during asexual reproduction. It may also act as a differentiation inducing factor. Galactose inhibits the cytostatic activity of TC14-3. The gene for Acorn worm PfG6 is gill-specific; PfG6 may be a secreted protein.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1433354043 201 YTNWNDGEPNNTGDGEDCVVILGN-GKWNDVPCSDSFLAICE 241
Cdd:cd03601    77 SDLWAPNEPSNPQSRQLCVQLWSKyNLLDDEYCGRAKRVICE 118