sixth (C-terminal) BRCT domain of Schizosaccharomyces pombe BRCT-containing protein 1 (BRC1) and similar proteins; Schizosaccharomyces pombe BRC1 is required for mitotic fidelity, specifically in the G2 phase of the cell cycle. It plays a role in chromatin organization. The family also includes Cryptococcus neoformans DNA ligase 4 (LIG4, also known as DNA ligase IV or polydeoxyribonucleotide synthase [ATP] 4), which is involved in dsDNA break repair, and plays a role in non-homologous integration (NHI) pathways where it is required in the final step of non-homologus end-joining. Members in this family contains six BRCT domains. This family corresponds to the sixth repeat.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1610174533 748 EKKLKMNLKESLERAKENEGKLLEGLTVYITPNVSPGFETFKKIVEANSGSALSFKAAKRGGiaaNKDASTSKRLVLVSV 827
Cdd:cd18439     1 EKKYGCTLAESLARAKANKGKLLKGYTVYLTPKVKGGVETFKSIVEANGGICNLLRAAKGKL---GDGIAEKGPVVLIST 77

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 1610174533 828 AKDDKLWPGFKRVAKESGWDPLVYSTDWLLDAAMTQKLV 866
Cdd:cd18439    78 TKEKKLWPKFLKNAREGGKEPRVYSTDWLLDVVLRQELV 116

second BRCT domain of Schizosaccharomyces pombe BRCT-containing protein 1 (BRC1) and similar proteins; Schizosaccharomyces pombe BRC1 is required for mitotic fidelity, specifically in the G2 phase of the cell cycle. It plays a role in chromatin organization. The family also includes Cryptococcus neoformans DNA ligase 4 (LIG4, also known as DNA ligase IV or polydeoxyribonucleotide synthase [ATP] 4), which is involved in dsDNA break repair, and plays a role in non-homologous integration (NHI) pathways where it is required in the final step of non-homologus end-joining. Members in this family contains six BRCT domains. This family corresponds to the second repeat.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1610174533 121 FSGIDAVIADLPEGDSEAICGGILAMGGLYKTNLSKLTTHIVALTLDNEICKTALE-KGLAAKIVMPHWFDDCLK 194
Cdd:cd18436     1 FSGVVITCSDLPSGDKEAIYGGVLALGGQYSDELTRDVTHLIALSPDGDKYKTALKrPELNIKIVLPHWFDDCFK 75

third BRCT domain of Schizosaccharomyces pombe BRCT-containing protein 1 (BRC1) and similar proteins; Schizosaccharomyces pombe BRC1 is required for mitotic fidelity, specifically in the G2 phase of the cell cycle. It plays a role in chromatin organization. The family also includes Cryptococcus neoformans DNA ligase 4 (LIG4, also known as DNA ligase IV or polydeoxyribonucleotide synthase [ATP] 4), which is involved in dsDNA break repair, and plays a role in non-homologous integration (NHI) pathways where it is required in the final step of non-homologus end-joining. Members in this family contains six BRCT domains. This family corresponds to the third repeat. The Trp-X-X-X-Cys/Ser signature motif of the BRCT family is not conserved in this group; it contains a conserved Trp, but not the Cys/Ser residue.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1610174533 254 KNFFFSGELGLNEKLLKIITDIVIQGSGKIATDIKNANVLVCPWRHGDDYIYASRKGIDVGNLTWLYWMTTRLEWVSP 331
Cdd:cd18437     1 KRFYLSADLNLGARRRKTISALIKGGGGKIVDTLADADIFIGRYRDGDEYLAASRSNKIVGNLSWLYHVLATGEWSSP 78

sixth (C-terminal) BRCT domain of Schizosaccharomyces pombe BRCT-containing protein 1 (BRC1) and similar proteins; Schizosaccharomyces pombe BRC1 is required for mitotic fidelity, specifically in the G2 phase of the cell cycle. It plays a role in chromatin organization. The family also includes Cryptococcus neoformans DNA ligase 4 (LIG4, also known as DNA ligase IV or polydeoxyribonucleotide synthase [ATP] 4), which is involved in dsDNA break repair, and plays a role in non-homologous integration (NHI) pathways where it is required in the final step of non-homologus end-joining. Members in this family contains six BRCT domains. This family corresponds to the sixth repeat.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1610174533 748 EKKLKMNLKESLERAKENEGKLLEGLTVYITPNVSPGFETFKKIVEANSGSALSFKAAKRGGiaaNKDASTSKRLVLVSV 827
Cdd:cd18439     1 EKKYGCTLAESLARAKANKGKLLKGYTVYLTPKVKGGVETFKSIVEANGGICNLLRAAKGKL---GDGIAEKGPVVLIST 77

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 1610174533 828 AKDDKLWPGFKRVAKESGWDPLVYSTDWLLDAAMTQKLV 866
Cdd:cd18439    78 TKEKKLWPKFLKNAREGGKEPRVYSTDWLLDVVLRQELV 116

second BRCT domain of Schizosaccharomyces pombe BRCT-containing protein 1 (BRC1) and similar proteins; Schizosaccharomyces pombe BRC1 is required for mitotic fidelity, specifically in the G2 phase of the cell cycle. It plays a role in chromatin organization. The family also includes Cryptococcus neoformans DNA ligase 4 (LIG4, also known as DNA ligase IV or polydeoxyribonucleotide synthase [ATP] 4), which is involved in dsDNA break repair, and plays a role in non-homologous integration (NHI) pathways where it is required in the final step of non-homologus end-joining. Members in this family contains six BRCT domains. This family corresponds to the second repeat.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1610174533 121 FSGIDAVIADLPEGDSEAICGGILAMGGLYKTNLSKLTTHIVALTLDNEICKTALE-KGLAAKIVMPHWFDDCLK 194
Cdd:cd18436     1 FSGVVITCSDLPSGDKEAIYGGVLALGGQYSDELTRDVTHLIALSPDGDKYKTALKrPELNIKIVLPHWFDDCFK 75

third BRCT domain of Schizosaccharomyces pombe BRCT-containing protein 1 (BRC1) and similar proteins; Schizosaccharomyces pombe BRC1 is required for mitotic fidelity, specifically in the G2 phase of the cell cycle. It plays a role in chromatin organization. The family also includes Cryptococcus neoformans DNA ligase 4 (LIG4, also known as DNA ligase IV or polydeoxyribonucleotide synthase [ATP] 4), which is involved in dsDNA break repair, and plays a role in non-homologous integration (NHI) pathways where it is required in the final step of non-homologus end-joining. Members in this family contains six BRCT domains. This family corresponds to the third repeat. The Trp-X-X-X-Cys/Ser signature motif of the BRCT family is not conserved in this group; it contains a conserved Trp, but not the Cys/Ser residue.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1610174533 254 KNFFFSGELGLNEKLLKIITDIVIQGSGKIATDIKNANVLVCPWRHGDDYIYASRKGIDVGNLTWLYWMTTRLEWVSP 331
Cdd:cd18437     1 KRFYLSADLNLGARRRKTISALIKGGGGKIVDTLADADIFIGRYRDGDEYLAASRSNKIVGNLSWLYHVLATGEWSSP 78

twin BRCT domain; This is a BRCT domain that appears in duplicate in most member sequences. BRCT domains are peptide- and phosphopeptide-binding modules. BRCT domains are present in a number of proteins involved in DNA checkpoint controls and DNA repair.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1610174533 351 MIISVSNYNGDARMYLENLIEAAGATFTRALKPENTHLITARDHSDKVDAAREWNTNIVNHLW 413
Cdd:pfam12738   1 LVICVTGFDGDDREGLQKLIEAMGAEYTKDLTKSVTHLICKSGEGEKYEKAKEWGIPVVSPLW 63

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1610174533 117 PRMIFSGIDAVIADLPEGDSEAICGGILAMGGLYKTNLSKLTTHIVALTlDNEICKTALEKGLaaKIVMPHWFDDCL 193
Cdd:pfam00533   2 KEKLFSGKTFVITGLDGLERDELKELIEKLGGKVTDSLSKKTTHVIVEA-RTKKYLKAKELGI--PIVTEEWLLDCI 75

sixth (C-terminal) BRCT domain of Schizosaccharomyces pombe BRCT-containing protein 1 (BRC1) and similar proteins; Schizosaccharomyces pombe BRC1 is required for mitotic fidelity, specifically in the G2 phase of the cell cycle. It plays a role in chromatin organization. The family also includes Cryptococcus neoformans DNA ligase 4 (LIG4, also known as DNA ligase IV or polydeoxyribonucleotide synthase [ATP] 4), which is involved in dsDNA break repair, and plays a role in non-homologous integration (NHI) pathways where it is required in the final step of non-homologus end-joining. Members in this family contains six BRCT domains. This family corresponds to the sixth repeat.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1610174533 748 EKKLKMNLKESLERAKENEGKLLEGLTVYITPNVSPGFETFKKIVEANSGSALSFKAAKRGGiaaNKDASTSKRLVLVSV 827
Cdd:cd18439     1 EKKYGCTLAESLARAKANKGKLLKGYTVYLTPKVKGGVETFKSIVEANGGICNLLRAAKGKL---GDGIAEKGPVVLIST 77

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 1610174533 828 AKDDKLWPGFKRVAKESGWDPLVYSTDWLLDAAMTQKLV 866
Cdd:cd18439    78 TKEKKLWPKFLKNAREGGKEPRVYSTDWLLDVVLRQELV 116

second BRCT domain of Schizosaccharomyces pombe BRCT-containing protein 1 (BRC1) and similar proteins; Schizosaccharomyces pombe BRC1 is required for mitotic fidelity, specifically in the G2 phase of the cell cycle. It plays a role in chromatin organization. The family also includes Cryptococcus neoformans DNA ligase 4 (LIG4, also known as DNA ligase IV or polydeoxyribonucleotide synthase [ATP] 4), which is involved in dsDNA break repair, and plays a role in non-homologous integration (NHI) pathways where it is required in the final step of non-homologus end-joining. Members in this family contains six BRCT domains. This family corresponds to the second repeat.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1610174533 121 FSGIDAVIADLPEGDSEAICGGILAMGGLYKTNLSKLTTHIVALTLDNEICKTALE-KGLAAKIVMPHWFDDCLK 194
Cdd:cd18436     1 FSGVVITCSDLPSGDKEAIYGGVLALGGQYSDELTRDVTHLIALSPDGDKYKTALKrPELNIKIVLPHWFDDCFK 75

third BRCT domain of Schizosaccharomyces pombe BRCT-containing protein 1 (BRC1) and similar proteins; Schizosaccharomyces pombe BRC1 is required for mitotic fidelity, specifically in the G2 phase of the cell cycle. It plays a role in chromatin organization. The family also includes Cryptococcus neoformans DNA ligase 4 (LIG4, also known as DNA ligase IV or polydeoxyribonucleotide synthase [ATP] 4), which is involved in dsDNA break repair, and plays a role in non-homologous integration (NHI) pathways where it is required in the final step of non-homologus end-joining. Members in this family contains six BRCT domains. This family corresponds to the third repeat. The Trp-X-X-X-Cys/Ser signature motif of the BRCT family is not conserved in this group; it contains a conserved Trp, but not the Cys/Ser residue.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1610174533 254 KNFFFSGELGLNEKLLKIITDIVIQGSGKIATDIKNANVLVCPWRHGDDYIYASRKGIDVGNLTWLYWMTTRLEWVSP 331
Cdd:cd18437     1 KRFYLSADLNLGARRRKTISALIKGGGGKIVDTLADADIFIGRYRDGDEYLAASRSNKIVGNLSWLYHVLATGEWSSP 78

twin BRCT domain; This is a BRCT domain that appears in duplicate in most member sequences. BRCT domains are peptide- and phosphopeptide-binding modules. BRCT domains are present in a number of proteins involved in DNA checkpoint controls and DNA repair.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1610174533 351 MIISVSNYNGDARMYLENLIEAAGATFTRALKPENTHLITARDHSDKVDAAREWNTNIVNHLW 413
Cdd:pfam12738   1 LVICVTGFDGDDREGLQKLIEAMGAEYTKDLTKSVTHLICKSGEGEKYEKAKEWGIPVVSPLW 63

sixth BRCT domain of PAX-interacting protein 1 (PAXIP1), second BRCT domain of mediator of DNA damage checkpoint protein 1 (MDC1) and similar proteins; PAXIP1, also termed PAX transactivation activation domain-interacting protein (PTIP), is involved in DNA damage response and in transcriptional regulation through histone methyltransferase (HMT) complexes. It also facilitates ATM-mediated activation of p53 and promotes cellular resistance to ionizing radiation. PAXIP1 contains six BRCT repeats. 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 sixth BRCT domain of PAXIP1 and the second BRCT domain of MDC1.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1610174533 769 LLEGLTVYITPNVSPGFETFKKIVEANSGSALSFKAAKRGGiaankdaSTSKRLVLVSVAKDDKLWPGFKR-VAKesgwd 847
Cdd:cd18432     1 LFEGYTFYVTPNVKPPPEELKEIIEAAGGKVLKKLPTKRIE-------DDDPDTIVISCEEDRKLWKPLKKkGIP----- 68

                          90
                  ....*....|....*...
gi 1610174533 848 plVYSTDWLLDAAMTQKL 865
Cdd:cd18432    69 --IYSVEFILTGILRQKL 84

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1610174533 351 MIISVSNYNGDARMYLENLIEAAGATFTRALKPENTHLITARDHSDKV-DAAREWNTNIVNHLWLEES 417
Cdd:cd00027     1 LVICFSGLDDEEREELKKLIEALGGKVSESLSSKVTHLIAKSPSGEKYyLAALAWGIPIVSPEWLLDC 68

fifth BRCT domain of PAX-interacting protein 1 (PAXIP1) and similar proteins; PAXIP1, also termed PAX transactivation activation domain-interacting protein (PTIP), is involved in DNA damage response and in transcriptional regulation through histone methyltransferase (HMT) complexes. It also facilitates ATM-mediated activation of p53 and promotes cellular resistance to ionizing radiation. PAXIP1 contains six BRCT repeats. This family corresponds to the fifth BRCT domain.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1610174533 670 PSREESDKRALREIGIQCIENPdAHVTHVCAPRVVRTEKFVCALARAPIIVNSNWVDECLKQKAIV 735
Cdd:cd17712    11 PVQVRKLTKKVTILGGEVVESP-QECTHLVAPKVSRTVKFLTAISVCKHIVTPEWLEESFKQGKFL 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        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1610174533 677 KRALREIGIQCIENP-DAhvTHVCAPRVVRTEKFVCALARAPIIVNSNWVDECLKQKAIV 735
Cdd:cd17744    15 EKIIKKLGGSVVDSVeDC--THLVTDKVRRTVKFLCALARGIPIVSPDWLEASIKANKFL 72

fifth BRCT domain of DNA topoisomerase 2-binding protein 1 (TopBP1) and similar proteins; TopBP1, also termed DNA topoisomerase II-beta-binding protein 1, or DNA topoisomerase II-binding protein 1, functions in DNA replication and damage response. It binds double-stranded DNA breaks and nicks as well as single-stranded DNA. TopBP1 contains six copies of BRCT domain. The family corresponds to the fifth BRCT domain.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 1610174533 352 IISVSNYNGDARMYLENLIEAAGAT----FTRALKPE-----NTHLITARDHSDKVDAAREWNTNIVNHLWLEES 417
Cdd:cd18434     6 VISVSQFTGTERDCLTHLAELLGAKvqdyFVRKANPSkgllaSTHLVLKEPEGSKYEAAKKWNLPAVTKSWLFEC 80

BRCT domain of DNA repair protein Rev1 and similar proteins; REV1, also termed alpha integrin-binding protein 80, or AIBP80, or Rev1-like terminal deoxycytidyl transferase, is a DNA template-dependent dCMP transferase required for mutagenesis induced by UV light.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1610174533 143 ILAMGGLYKTNLSK-LTTHIVALTLDNEicKT-ALEKGLAAKIVMPHWFDDCLKLNRRIDETPYLL 206
Cdd:cd17719    24 ILLHGGQYEHYYSRsRVTHIIATNLPGS--KIkKLKKARNYKVVRPEWIVDSIKAGRLLPEAPYLL 87

BRCT domain of nibrin and similar proteins; Nibrin (NBN), also termed Nijmegen breakage syndrome protein 1 (NBS1), or cell cycle regulatory protein p95, is a novel DNA double-strand break repair protein that is mutated in Nijmegen breakage syndrome. It is a component of the MRE11-RAD50-NBN (MRN complex) which plays a critical role in the cellular response to DNA damage and the maintenance of chromosome integrity. The BRCT (Breast Cancer Suppressor Protein BRCA1, carboxy-terminal) domain is found within many DNA damage repair and cell cycle checkpoint proteins. The unique diversity of this domain superfamily allows BRCT modules to interact forming homo/hetero BRCT multimers, BRCT-non-BRCT interactions, and interactions within DNA strand breaks. The Trp-X-X-X-Cys/Ser signature motif of the BRCT family is absent in this group.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1610174533 677 KRALREIGIQCIENPDAHVTHVCAPRVVRTEKFVCALARAPIIVNSNWVDECLK 730
Cdd:cd17741    19 KQIIAKLGGKVVNEWTEECTHLVMSKIKVTVKVICALISGKPIVTPEYLDALLE 72

seventh BRCT domain of DNA topoisomerase 2-binding protein 1; TopBP1, also termed DNA topoisomerase II-beta-binding protein 1, or DNA topoisomerase II-binding protein 1, functions in DNA replication and damage response. It binds double-stranded DNA breaks and nicks as well as single-stranded DNA. TopBP1 contains six copies of BRCT domain. The family corresponds to the seventh BRCT domain. The Trp-X-X-X-Cys/Ser signature motif of the BRCT family is missing in this group.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1610174533 680 LREIGIQCIE--NPDAHVTHVCAPRVVRTEKFVCALARAPIIVNSNWVDECLKQK 732
Cdd:cd17738    21 IEKLGGKVLDsdEFDPKCTHLICGKPSRSEKFLAACAAGKWILHPSYIEASAKAG 75

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1610174533 117 PRMIFSGIDAVIADLPEGDSEAICGGILAMGGLYKTNLSKLTTHIVALTlDNEICKTALEKGLaaKIVMPHWFDDCL 193
Cdd:pfam00533   2 KEKLFSGKTFVITGLDGLERDELKELIEKLGGKVTDSLSKKTTHVIVEA-RTKKYLKAKELGI--PIVTEEWLLDCI 75

First (central) BRCT domain in X-ray repair cross-complementing protein 1 (XRCC1) and similar proteins; XRCC1 is a DNA repair protein that corrects defective DNA strand-break repair and sister chromatid exchange following treatment with ionizing radiation and alkylating agents. It forms homodimers and interacts with polynucleotide kinase (PNK), DNA polymerase-beta (POLB), DNA ligase III (LIG3), APTX, APLF, and APEX1. XRCC1 contains an N-terminal XRCC1-specific domain and two BRCT domains. This family corresponds to the first one.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1610174533 670 PSREESDKRALrEIGIQCIENPDAHVTH-VCAprVVRTEKFVCALARAPIIVNSNWVDECLKQKAIVDTKPY 740
Cdd:cd17725    12 PFRGELRDKAL-EMGAKYRPDWTADCTHlICA--FANTPKYKQVKGAGGIIVSKEWILDCYKKKKRLPWKRY 80

breast cancer carboxy-terminal domain;

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|..
gi 1610174533  143 ILAMGGLYKTNLSKL-TTHIVALTLDNEICKTALEKGLAAKIVMPHWFDDCL 193
Cdd:smart00292  27 IEALGGKVTSSLSSKtTTHVIVGSPEGGKLELLKAIALGIPIVKEEWLLDCL 78

second BRCT domain of Schizosaccharomyces pombe S-M checkpoint control protein Rad4 and similar proteins; Rad4, also termed P74, or protein cut5, is an essential component for DNA replication and the checkpoint control system which couples S and M phases. It may directly or indirectly interact with chromatin proteins to form the complex required for the initiation and/or progression of DNA synthesis. Rad4 contains four BRCT repeats. The family corresponds to the second one.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1610174533 345 IPGMEEMIISVSNYNGDARMYLENLIEAAGATFTRALKPENTHLITARDHSDKVDAAREWNTNIVNHLWLEES 417
Cdd:cd17746     4 LPTLFKCRVCLTNIGQPERSRIENYVLKHGGTFCPDLTRDVTHLIAGTSSGRKYEYALKWKINVVCVEWLWQS 76

First (central) BRCT domain in X-ray repair cross-complementing protein 1 (XRCC1) and similar proteins; XRCC1 is a DNA repair protein that corrects defective DNA strand-break repair and sister chromatid exchange following treatment with ionizing radiation and alkylating agents. It forms homodimers and interacts with polynucleotide kinase (PNK), DNA polymerase-beta (POLB), DNA ligase III (LIG3), APTX, APLF, and APEX1. XRCC1 contains an N-terminal XRCC1-specific domain and two BRCT domains. This family corresponds to the first one.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1610174533 144 LAMGGLYKTNLSKLTTHIVALTLDNEICKTAleKGLAAKIVMPHWFDDCLKLNRRIDETPY 204
Cdd:cd17725    22 LEMGAKYRPDWTADCTHLICAFANTPKYKQV--KGAGGIIVSKEWILDCYKKKKRLPWKRY 80

BRCT domain, a BRCA1 C-terminus domain; This BRCT domain, a BRCA1 C-terminus region, is found on many RAP1 proteins, usually at the very N-terminus. The function in human at least of a BRCT is to contribute to the heterogeneity of the telomere DNA length, but that may not be its general function, which remains unknown.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1610174533 349 EEMIISVSNYNGDARMYLENLIEAAGATFTRALKPENTHLITARdhSDKVDAAREWNTNIVNHLWLEES 417
Cdd:pfam16589   6 EPLRFYINAIPSPSRSKLKRLIEANGGTVVDNINPAVYIVIAPY--NKTDKLAENTKLGVVSPQWIFDC 72

third BRCT domain of PAX-interacting protein 1 (PAXIP1) and similar proteins; PAXIP1, also termed PAX transactivation activation domain-interacting protein (PTIP), is involved in DNA damage response and in transcriptional regulation through histone methyltransferase (HMT) complexes. It also facilitates ATM-mediated activation of p53 and promotes cellular resistance to ionizing radiation. PAXIP1 contains six BRCT repeats. This family corresponds to the third BRCT domain.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1610174533 143 ILAMGGLYKTNLSKLTTHIVALTLDNEICKTALEKGLAakIVMPHWFDDCLK 194
Cdd:cd17711    25 IEEHGGEVVDEYSPRVTHVICESQDSPEYQQALRDGKR--VVTAYWLNDVLK 74

BRCT domain, a BRCA1 C-terminus domain; This BRCT domain, a BRCA1 C-terminus region, is found on many RAP1 proteins, usually at the very N-terminus. The function in human at least of a BRCT is to contribute to the heterogeneity of the telomere DNA length, but that may not be its general function, which remains unknown.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1610174533 120 IFSGIDAVIADLPEGDSEAICGGILAMGGLYKTNLSKLTTHIVAltldNEICKTALEKGLAAKIVMPHWFDDCLKLNRRI 199
Cdd:pfam16589   4 LFEPLRFYINAIPSPSRSKLKRLIEANGGTVVDNINPAVYIVIA----PYNKTDKLAENTKLGVVSPQWIFDCVKKGKLL 79

                  ....*
gi 1610174533 200 DETPY 204
Cdd:pfam16589  80 PLENY 84