3olc

Publication Abstract from PubMed

Human DNA Topoisomerase IIbeta binding protein 1 (TopBP1) is a modulating protein that plays an essential role in the response to DNA damage. The N-terminal region of TopBP1, which contains predicted BRCA1-carboxy terminal (BRCT) domains 1 and 2, binds to Rad9, a component of the cell cycle checkpoint clamp Rad9-Hus1-Rad1 complex. Here, we report the crystal structure of the TopBP1N-terminal region (residues 1-290) at 2.4A resolution. Interestingly, in addition to the predicted tandem BRCT1-2 repeats (residues 103-284), residues 7-98 form a previously unreported BRCT domain (here, BRCT0). In contrast to both BRCT1 and BRCT2, which possess the conventional phosphopeptide binding residues within a surface pocket, the corresponding pocket in BRCT0 is largely hydrophobic. Structural comparisons together with peptide binding studies indicate that the tandem BRCT1-2 domains are the binding region for phosphorylated Ser387 in Rad9.

Crystal structure of the N-terminal region of human Topoisomerase IIbeta binding protein 1.,Huo YG, Bai L, Xu M, Jiang T Biochem Biophys Res Commun. 2010 Oct 22;401(3):401-5. Epub 2010 Sep 19. PMID:20858457^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.