ECT2 (Epithelial Cell Transforming Sequence 2) is a guanine nucleotide exchange factor (GEF) that catalyses the exchange of GDP for GTP. It is a cell cycle regulator that plays key roles in cytokinesis [1-4]. ECT2 contains triple copies of the BRCT d ...
ECT2 (Epithelial Cell Transforming Sequence 2) is a guanine nucleotide exchange factor (GEF) that catalyses the exchange of GDP for GTP. It is a cell cycle regulator that plays key roles in cytokinesis [1-4]. ECT2 contains triple copies of the BRCT domain (BRCT0, BRCT1 (Pfam:PF12738) and BRCT2 (Pfam:PF00533) at the N-terminal, separated from the C-terminal DH (Pfam:PF00621) and PH (Pfam:PF21242) domains by a linker of about 100 residues. This entry represents the first BRCT domain, BRCT0 [3]. The BRCT and DH-PH domains mediate intra-molecular interactions that restrains ETC2 activity during interphase.
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 [1,2].
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- ...
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 [2]. Structures of the BRCA1 BRCT domains revealed a basis for a widely utilised head-to-tail BRCT-BRCT oligomerisation mode [3]. 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 [5].
