3al3

From Proteopedia

Crystal Structure of TopBP1 BRCT7/8-BACH1 peptide complex

Structural highlights

3al3 is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.15Å
Ligands:	,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

TOPB1_HUMAN Required for DNA replication. Plays a role in the rescue of stalled replication forks and checkpoint control. Binds double-stranded DNA breaks and nicks as well as single-stranded DNA. Recruits the SWI/SNF chromatin remodeling complex to E2F1-responsive promoters. Down-regulates E2F1 activity and inhibits E2F1-dependent apoptosis during G1/S transition and after DNA damage. Induces a large increase in the kinase activity of ATR.^[1] ^[2] ^[3] ^[4] ^[5] ^[6]

Publication Abstract from PubMed

The diverse roles of TopBP1 in DNA replication and checkpoint signaling are associated with the scaffolding ability of TopBP1 to initiate various protein-protein interactions. The recognition of the BACH1/FANCJ helicase by TopBP1 is critical for the activation of the DNA replication checkpoint at stalled replication forks and is facilitated by the C-terminal tandem BRCT7/8 domains of TopBP1 and a phosphorylated Thr(1133) binding motif in BACH1. Here we provide the structural basis for this interaction through analysis of the x-ray crystal structures of TopBP1 BRCT7/8 both free and in complex with a BACH1 phospho-peptide. In contrast to canonical BRCT-phospho-peptide recognition, TopBP1 BRCT7/8 undergoes a dramatic conformational change upon BACH1 binding such that the two BRCT repeats pivot about the central BRCT-BRCT interface to provide an extensive and deep peptide-binding cleft. Additionally, we provide the first structural mechanism for Thr(P) recognition among BRCT domains. Together with systematic mutagenesis studies, we highlight the role of key contacts in governing the unique specificity of the TopBP1-BACH1 interaction.

Molecular basis of BACH1/FANCJ recognition by TopBP1 in DNA replication checkpoint control.,Leung CC, Gong Z, Chen J, Glover JN J Biol Chem. 2011 Feb 11;286(6):4292-301. Epub 2010 Dec 2. PMID:21127055^[7]

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

References

↑ Yamane K, Tsuruo T. Conserved BRCT regions of TopBP1 and of the tumor suppressor BRCA1 bind strand breaks and termini of DNA. Oncogene. 1999 Sep 16;18(37):5194-203. PMID:10498869 doi:10.1038/sj.onc.1202922
↑ Makiniemi M, Hillukkala T, Tuusa J, Reini K, Vaara M, Huang D, Pospiech H, Majuri I, Westerling T, Makela TP, Syvaoja JE. BRCT domain-containing protein TopBP1 functions in DNA replication and damage response. J Biol Chem. 2001 Aug 10;276(32):30399-406. Epub 2001 Jun 6. PMID:11395493 doi:10.1074/jbc.M102245200
↑ Honda Y, Tojo M, Matsuzaki K, Anan T, Matsumoto M, Ando M, Saya H, Nakao M. Cooperation of HECT-domain ubiquitin ligase hHYD and DNA topoisomerase II-binding protein for DNA damage response. J Biol Chem. 2002 Feb 1;277(5):3599-605. Epub 2001 Nov 19. PMID:11714696 doi:10.1074/jbc.M104347200
↑ Liu K, Lin FT, Ruppert JM, Lin WC. Regulation of E2F1 by BRCT domain-containing protein TopBP1. Mol Cell Biol. 2003 May;23(9):3287-304. PMID:12697828
↑ Liu K, Luo Y, Lin FT, Lin WC. TopBP1 recruits Brg1/Brm to repress E2F1-induced apoptosis, a novel pRb-independent and E2F1-specific control for cell survival. Genes Dev. 2004 Mar 15;18(6):673-86. PMID:15075294 doi:10.1101/gad.1180204
↑ Kumagai A, Lee J, Yoo HY, Dunphy WG. TopBP1 activates the ATR-ATRIP complex. Cell. 2006 Mar 10;124(5):943-55. PMID:16530042 doi:10.1016/j.cell.2005.12.041
↑ Leung CC, Gong Z, Chen J, Glover JN. Molecular basis of BACH1/FANCJ recognition by TopBP1 in DNA replication checkpoint control. J Biol Chem. 2011 Feb 11;286(6):4292-301. Epub 2010 Dec 2. PMID:21127055 doi:10.1074/jbc.M110.189555