first BRCT domain of breast cancer type 1 susceptibility protein (BRCA1) and similar proteins; BRCA1, also termed RING finger protein 53 (RNF53), is a RING finger protein encoded by BRCA1, a tumor suppressor gene that regulates all DNA double-strand break (DSB) repair pathways. BRCA1 is frequently mutated in patients with hereditary breast and ovarian cancer (HBOC). Its mutation is also associated with an increased risk of pancreatic, stomach, laryngeal, fallopian tube, and prostate cancer. It plays an important role in the DNA damage response signaling, and has been implicated in various cellular processes such as cell cycle regulation, transcriptional regulation, chromatin remodeling, DNA DSBs, and apoptosis. BRCA1 contains an N-terminal C3HC4-type RING-HC finger, and two BRCT (BRCA1 C-terminus domain) repeats at the C-terminus. The family corresponds to the first BRCT domain.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1825909207 1498 MSLVVSGLTPEEFMLVYKFARRYHIALTNLITEETTHVVMKTDAEFVCERTLKYFLGIAGGKWVVSYFWVTQSIKERKML 1577
Cdd:cd17735      1 MSMVASGLTPEELMLVQKFARKTGSTLTSQFTEETTHVIMKTDAELVCERTLKYFLGIAGRKWVVSYQWITQSIKEGKIL 80

                           90
                   ....*....|....*..
gi 1825909207 1578 NEHDFEVRGDVVNGRNH 1594
Cdd:cd17735     81 PEHDFEVRGDVVNGRNH 97

RING finger (Really Interesting New Gene) domain and U-box domain superfamily; The RING finger is a specialized type of Zn-finger of 40 to 60 residues that binds two atoms of zinc. It is defined by the "cross-brace" motif that chelates zinc atoms by eight amino acid residues, typically Cys or His, arranged in a characteristic spacing. Canonical RING motifs have been categorized into two major subclasses, RING-HC (C3HC4-type) and RING-H2 (C3H2C3-type), according to their Cys/His content. There are also many variants of RING fingers: some have different Cys/His patterns while some lack a single Cys or His residue at typical Zn ligand positions (the fourth or eighth zinc ligand is prevalently exchanged for an Asp, which can indeed chelate Zn in a RING finger as well). C4C4-, C3HC3D-, C2H2C4-, and C3HC5-type RING fingers are closely related to RING-HC fingers. In contrast, C4HC3- (RING-CH alias RINGv), C3H3C2-, C3H2C2D-, C3DHC3-, and C4HC2H-type RING fingers are more closely related to RING-H2 fingers. However, not all RING finger-containing proteins display regular RING finger features, and the RING finger family has turned out to be multifarious. The degenerate RING fingers of the Siz/PIAS RING (SP-RING) family proteins and sporulation protein RMD5, are characterized by lacking the second, fifth, and sixth Zn2+ ion-coordinating residues. They bind only one Zn2+ ion. On the other hand, the RING fingers of the human APC11 and RBX1 proteins can bind a third Zn atom since they harbor four additional Zn ligands. U-box is a modified form of the RING finger domain that lacks metal chelating Cys and His residues. It resembles the cross-brace RING structure consisting of three beta-sheets and a single alpha-helix, which would be stabilized by salt bridges instead of chelated metal ions. U-box proteins are widely distributed among eukaryotic organisms and show a higher prevalence in plants than in other organisms. RING finger/U-box-containing proteins are a group of diverse proteins with a variety of cellular functions, including oncogenesis, development, viral replication, signal transduction, the cell cycle and apoptosis. Many of them are ubiquitin-protein ligases (E3s) that serve as scaffolds for binding to ubiquitin-conjugating enzymes (E2s, also referred to as ubiquitin carrier proteins or UBCs) in close proximity to substrate proteins, which enable efficient transfer of ubiquitin from E2 to the substrates.

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|..
gi 1825909207    1 MLKLLNQKKGPSQCPLCKNDITKRSLQESTRFSQLVEELLKIIHAFQLDTGL 52
Cdd:cd16498     43 ILKLLQKKKKPAPCPLCKKSVTKRSLQESTRFKQLVEAVKKLIDAFELDTGL 94

first BRCT domain of breast cancer type 1 susceptibility protein (BRCA1) and similar proteins; BRCA1, also termed RING finger protein 53 (RNF53), is a RING finger protein encoded by BRCA1, a tumor suppressor gene that regulates all DNA double-strand break (DSB) repair pathways. BRCA1 is frequently mutated in patients with hereditary breast and ovarian cancer (HBOC). Its mutation is also associated with an increased risk of pancreatic, stomach, laryngeal, fallopian tube, and prostate cancer. It plays an important role in the DNA damage response signaling, and has been implicated in various cellular processes such as cell cycle regulation, transcriptional regulation, chromatin remodeling, DNA DSBs, and apoptosis. BRCA1 contains an N-terminal C3HC4-type RING-HC finger, and two BRCT (BRCA1 C-terminus domain) repeats at the C-terminus. The family corresponds to the first BRCT domain.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1825909207 1498 MSLVVSGLTPEEFMLVYKFARRYHIALTNLITEETTHVVMKTDAEFVCERTLKYFLGIAGGKWVVSYFWVTQSIKERKML 1577
Cdd:cd17735      1 MSMVASGLTPEELMLVQKFARKTGSTLTSQFTEETTHVIMKTDAELVCERTLKYFLGIAGRKWVVSYQWITQSIKEGKIL 80

                           90
                   ....*....|....*..
gi 1825909207 1578 NEHDFEVRGDVVNGRNH 1594
Cdd:cd17735     81 PEHDFEVRGDVVNGRNH 97

RING finger, HC subclass, found in breast cancer type 1 susceptibility protein (BRCA1) and similar proteins; BRCA1, also known as RING finger protein 53 (RNF53), is a RING finger protein encoded by the tumor suppressor gene BRCA1 that regulates all DNA double-strand break (DSB) repair pathways. BRCA1 is frequently mutated in patients with hereditary breast and ovarian cancer (HBOC). Its mutation is also associated with an increased risk of pancreatic, stomach, laryngeal, fallopian tube, and prostate cancer. It plays an important role in the DNA damage response signaling and has been implicated in various cellular processes such as cell cycle regulation, transcriptional regulation, chromatin remodeling, DNA DSBs, and apoptosis. BRCA1 contains an N-terminal C3HC4-type RING-HC finger, and two BRCT (BRCA1 C-terminus domain) repeats at the C-terminus.

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|..
gi 1825909207    1 MLKLLNQKKGPSQCPLCKNDITKRSLQESTRFSQLVEELLKIIHAFQLDTGL 52
Cdd:cd16498     43 ILKLLQKKKKPAPCPLCKKSVTKRSLQESTRFKQLVEAVKKLIDAFELDTGL 94

BRCA1 C Terminus (BRCT) domain; The BRCT domain is found predominantly in proteins involved in cell cycle checkpoint functions responsive to DNA damage. The BRCT domain of XRCC1 forms a homodimer in the crystal structure. This suggests that pairs of BRCT domains associate as homo- or heterodimers. BRCT domains are often found as tandem-repeat pairs. Structures of the BRCA1 BRCT domains revealed a basis for a widely utilized head-to-tail BRCT-BRCT oligomerization mode. This conserved tandem BRCT architecture facilitates formation of the canonical BRCT phospho-peptide interaction cleft at a groove between the BRCT domains. Disease associated missense and nonsense mutations in the BRCA1 BRCT domains disrupt peptide binding by directly occluding this peptide binding groove, or by disrupting key conserved BRCT core folding determinants.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1825909207 1604 PDRKIFRGLEICCYGpFTNMPTDQLEWMVQLCGASVVKELSSFTlgtgfHPVVVVqpdawtEDNGFHAIGRMCEAPVVTR 1683
Cdd:pfam00533    1 PKEKLFSGKTFVITG-LDGLERDELKELIEKLGGKVTDSLSKKT-----THVIVE------ARTKKYLKAKELGIPIVTE 68

                   ....*..
gi 1825909207 1684 EWVLDSV 1690
Cdd:pfam00533   69 EWLLDCI 75

first BRCT domain of breast cancer type 1 susceptibility protein (BRCA1) and similar proteins; BRCA1, also termed RING finger protein 53 (RNF53), is a RING finger protein encoded by BRCA1, a tumor suppressor gene that regulates all DNA double-strand break (DSB) repair pathways. BRCA1 is frequently mutated in patients with hereditary breast and ovarian cancer (HBOC). Its mutation is also associated with an increased risk of pancreatic, stomach, laryngeal, fallopian tube, and prostate cancer. It plays an important role in the DNA damage response signaling, and has been implicated in various cellular processes such as cell cycle regulation, transcriptional regulation, chromatin remodeling, DNA DSBs, and apoptosis. BRCA1 contains an N-terminal C3HC4-type RING-HC finger, and two BRCT (BRCA1 C-terminus domain) repeats at the C-terminus. The family corresponds to the first BRCT domain.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1825909207 1498 MSLVVSGLTPEEFMLVYKFARRYHIALTNLITEETTHVVMKTDAEFVCERTLKYFLGIAGGKWVVSYFWVTQSIKERKML 1577
Cdd:cd17735      1 MSMVASGLTPEELMLVQKFARKTGSTLTSQFTEETTHVIMKTDAELVCERTLKYFLGIAGRKWVVSYQWITQSIKEGKIL 80

                           90
                   ....*....|....*..
gi 1825909207 1578 NEHDFEVRGDVVNGRNH 1594
Cdd:cd17735     81 PEHDFEVRGDVVNGRNH 97

RING finger, HC subclass, found in breast cancer type 1 susceptibility protein (BRCA1) and similar proteins; BRCA1, also known as RING finger protein 53 (RNF53), is a RING finger protein encoded by the tumor suppressor gene BRCA1 that regulates all DNA double-strand break (DSB) repair pathways. BRCA1 is frequently mutated in patients with hereditary breast and ovarian cancer (HBOC). Its mutation is also associated with an increased risk of pancreatic, stomach, laryngeal, fallopian tube, and prostate cancer. It plays an important role in the DNA damage response signaling and has been implicated in various cellular processes such as cell cycle regulation, transcriptional regulation, chromatin remodeling, DNA DSBs, and apoptosis. BRCA1 contains an N-terminal C3HC4-type RING-HC finger, and two BRCT (BRCA1 C-terminus domain) repeats at the C-terminus.

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|..
gi 1825909207    1 MLKLLNQKKGPSQCPLCKNDITKRSLQESTRFSQLVEELLKIIHAFQLDTGL 52
Cdd:cd16498     43 ILKLLQKKKKPAPCPLCKKSVTKRSLQESTRFKQLVEAVKKLIDAFELDTGL 94

second BRCT domain of microcephalin and similar proteins; Microcephalin is a DNA damage response protein involved in regulation of CHK1 and BRCA1. It has been implicated in chromosome condensation and DNA damage induced cellular responses. It may play a role in neurogenesis and regulation of the size of the cerebral cortex. Microcephalin contains three BRCT repeats. This family corresponds to the second repeat.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1825909207 1498 MSLVVSGLTPEEFMLVYKFARRY-HIALTNLITEETTHVVMKTDAefvceRTLKYFLGIAGGKWVVSYFWVTQSIKERKM 1576
Cdd:cd17736      1 RTLVMTSVHSEEQELLESVVKKLgGFRVEDSVTEKTTHVVVGSPR-----RTLNVLLGIARGCWILSPDWVLESLEAGKW 75

                   .
gi 1825909207 1577 L 1577
Cdd:cd17736     76 L 76

C-terminal domain of the breast cancer suppressor protein (BRCA1) and related domains; The BRCT (BRCA1 C-terminus) domain is found within many DNA damage repair and cell cycle checkpoint proteins. BRCT domains interact with each other forming homo/hetero BRCT multimers, but are also involved in BRCT-non-BRCT interactions and interactions within DNA strand breaks. BRCT tandem repeats bind to phosphopeptides; it has been shown that the repeats in human BRCA1 bind specifically to pS-X-X-F motifs, mediating the interaction between BRCA1 and the DNA helicase BACH1, or BRCA1 and CtIP, a transcriptional corepressor. It is assumed that BRCT repeats play similar roles in many signaling pathways associated with the response to DNA damage.

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1825909207 1498 MSLVVSGLTPEEFMLVYKFARRYHIALTNLITEETTHVVMKTDaefvcERTLKYFLGIAGGKWVVSYFWVTQS 1570
Cdd:cd00027      1 LVICFSGLDDEEREELKKLIEALGGKVSESLSSKVTHLIAKSP-----SGEKYYLAALAWGIPIVSPEWLLDC 68

BRCA1 C Terminus (BRCT) domain; The BRCT domain is found predominantly in proteins involved in cell cycle checkpoint functions responsive to DNA damage. The BRCT domain of XRCC1 forms a homodimer in the crystal structure. This suggests that pairs of BRCT domains associate as homo- or heterodimers. BRCT domains are often found as tandem-repeat pairs. Structures of the BRCA1 BRCT domains revealed a basis for a widely utilized head-to-tail BRCT-BRCT oligomerization mode. This conserved tandem BRCT architecture facilitates formation of the canonical BRCT phospho-peptide interaction cleft at a groove between the BRCT domains. Disease associated missense and nonsense mutations in the BRCA1 BRCT domains disrupt peptide binding by directly occluding this peptide binding groove, or by disrupting key conserved BRCT core folding determinants.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1825909207 1492 ERVNKRMSLVVSGLTPEEFMLVYKFARRYHIALTNLITEETTHVVmktdaefVCERTLKYFLGIAGGKWVVSYFWVTQSI 1571
Cdd:pfam00533    3 EKLFSGKTFVITGLDGLERDELKELIEKLGGKVTDSLSKKTTHVI-------VEARTKKYLKAKELGIPIVTEEWLLDCI 75

first BRCT domain of mediator of DNA damage checkpoint protein 1 (MDC1) and similar proteins; MDC1, also termed nuclear factor with BRCT domains 1 (NFBD1), is a nuclear chromatin-associated protein that is required for checkpoint mediated cell cycle arrest in response to DNA damage within both the S phase and G2/M phases of the cell cycle. It directly binds phosphorylated histone H2AX to regulate cellular responses to DNA double-strand breaks. MDC1 contains a forkhead-associated (FHA) domain and two BRCT domains, as well as an internal 41-amino acid repeat sequence. The family corresponds to the first BRCT domain.

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*...
gi 1825909207 1530 EETTHVVmkTDAEfvcERTLKYFLGIAGGKWVVSYFWVTQSIKERKML 1577
Cdd:cd17744     30 EDCTHLV--TDKV---RRTVKFLCALARGIPIVSPDWLEASIKANKFL 72