title: Consequences of cisplatin binding on nucleosome structure and dynamics.
abstract: The effects of cisplatin binding to DNA were explored at the nucleosome level to incorporate key features of the eukaryotic nuclear environment. An X-ray crystal structure of a site-specifically platinated nucleosome carrying a 1,3-cis-{Pt(NH₃)₂}²+-d(GpTpG) intrastrand cross-link reveals the details of how this adduct dictates the rotational positioning of DNA in the nucleosome. Results from in vitro nucleosome mobility assays indicate that a single platinum adduct interferes with ATP-independent sliding of DNA around the octamer core. Data from in vitro transcription experiments suggest that RNA polymerases can successfully navigate along cisplatin-damaged DNA templates that contain nucleosomes, but stall when the transcription elongation complex physically contacts a platinum cross-link located on the template strand. These results provide information about the effects of cisplatin binding to nuclear DNA and enhance our understanding of the mechanism of transcription inhibition by platinum anticancer compounds.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Todd
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Lippard
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry*; D002945:Cisplatin / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry; D018736:DNA Adducts / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D056004:Molecular Dynamics Simulation; D009707:Nucleosomes / Q000737:chemistry*; D011485:Protein Binding; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D018736:DNA Adducts; D009707:Nucleosomes; D014764:Viral Proteins; D004247:DNA; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases; D002945:Cisplatin