1ckt
From Proteopedia
CRYSTAL STRUCTURE OF HMG1 DOMAIN A BOUND TO A CISPLATIN-MODIFIED DNA DUPLEX
Structural highlights
FunctionHMGB1_RAT DNA binding proteins that associates with chromatin and has the ability to bend DNA. Binds preferentially single-stranded DNA. Involved in V(D)J recombination by acting as a cofactor of the RAG complex. Acts by stimulating cleavage and RAG protein binding at the 23 bp spacer of conserved recombination signal sequences (RSS). Heparin-binding protein that has a role in the extension of neurite-type cytoplasmic processes in developing cells (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe anticancer activity of cis-diamminedichloroplatinum(II) (cisplatin) arises from its ability to damage DNA, with the major adducts formed being intrastrand d(GpG) and d(ApG) crosslinks. These crosslinks bend and unwind the duplex, and the altered structure attracts high-mobility-group domain (HMG) and other proteins. This binding of HMG-domain proteins to cisplatin-modified DNA has been postulated to mediate the antitumour properties of the drug. Many HMG-domain proteins recognize altered DNA structures such as four-way junctions and cisplatin-modified DNA, but until now the molecular basis for this recognition was unknown. Here we describe mutagenesis, hydroxyl-radical footprinting and X-ray studies that elucidate the structure of a 1:1 cisplatin-modified DNA/HMG-domain complex. Domain A of the structure-specific HMG-domain protein HMG1 binds to the widened minor groove of a 16-base-pair DNA duplex containing a site-specific cis-[Pt(NH3)2[d(GpG)-N7(1),-N7(2)]] adduct. The DNA is strongly kinked at a hydrophobic notch created at the platinum-DNA crosslink and protein binding extends exclusively to the 3' side of the platinated strand. A phenylalanine residue at position 37 intercalates into a hydrophobic notch created at the platinum crosslinked d(GpG) site and binding of the domain is dramatically reduced in a mutant in which alanine is substituted for phenylalanine at this position. Basis for recognition of cisplatin-modified DNA by high-mobility-group proteins.,Ohndorf UM, Rould MA, He Q, Pabo CO, Lippard SJ Nature. 1999 Jun 17;399(6737):708-12. PMID:10385126[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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