title: Photobinding of 8-methoxypsoralen and changes in nuclease digestability of replicating SV40 chromatin.
abstract: To analyze the structure of the replicating regions of simian virus 40 nucleoprotein complex (SV40 chromatin), photochemical binding of 8-methoxypsoralen (8-MOP) and changes in digestability with micrococcal nuclease were studied. 8-MOP bound preferentially to the linker DNA of nucleosomes and strongly inhibited nuclease digestion. Nuclease digestability of newly synthesized DNA in the replicating chromatin was markedly increased, but it was inhibited in the early time of nuclease reaction by photobinding of 8-MOP. The data suggest that the replicating regions of chromatin are more exposed than the bulk of mature chromatin.
mesh_terms: D002843:Chromatin / Q000187:drug effects*; D004261:DNA Replication / Q000187:drug effects*; D007700:Kinetics; D008730:Methoxsalen / Q000494:pharmacology; D008836:Micrococcal Nuclease / Q000378:metabolism*; D010777:Photochemistry; D013539:Simian virus 40 / Q000187:drug effects / Q000378:metabolism*; D014779:Virus Replication / Q000187:drug effects
chemical_list: D002843:Chromatin; D008836:Micrococcal Nuclease; D008730:Methoxsalen