Publication Abstract from PubMed
Mcph1 is mutated in autosomal recessive primary microcephaly and premature chromosome condensation (PCC) syndrome. Increased chromosome condensation is a common feature of cells isolated from patients afflicted with either disease. Normal cells depleted of Mcph1 also exhibit PCC phenotype. Human Mcph1 contains three BRCA1-carboxyl terminal (BRCT) domains, the first of which (Mcph1N) is necessary for the prevention of PCC. The only known disease-associated missense mutation in Mcph1 resides in this domain (T27R). We have determined the X-ray crystal structure of human Mcph1N to 1.6 A resolution. Compared with other BRCT domain structures, the most striking differences are an elongated, ordered beta1-alpha1 loop and an adjacent hydrophobic pocket. This pocket is in the equivalent structural position to the phosphate binding site of BRCT domains that recognize phospho-proteins, although the phosphate-binding residues are absent in Mcph1N. Mutations in the pocket abrogate the ability of full-length Mcph1 to rescue the PCC phenotype of Mcph1(-/-) mouse embryonic fibroblast cells, suggesting that it forms an essential part of a protein-protein interaction site necessary to prevent PCC.
A pocket on the surface of the N-terminal BRCT domain of Mcph1 is required to prevent abnormal chromosome condensation.,Richards MW, Leung JW, Roe SM, Li K, Chen J, Bayliss R J Mol Biol. 2010 Feb 5;395(5):908-15. Epub 2009 Nov 17. PMID:19925808[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
