title: Diepoxybutane and diepoxyoctane interstrand cross-linking of the 5S DNA nucleosomal core particle.
abstract: Diepoxyalkanes form interstrand cross-links in DNA oligomers preferentially at 5'-GNC sites. We have examined cross-linking by 1,2,3,4-diepoxybutane (DEB) and 1,2,7,8-diepoxyoctane (DEO) within a fragment of the 5S RNA gene of Xenopus borealis in both the free and nucleosomal states. Sites and efficiencies of interstrand cross-linking were probed through denaturing polyacrylamide gel electrophoresis and quantitative phosphorimagery. Both agents targeted 5'-GNC sites for cross-linking in the restriction fragment in its free state, and DEO also targeted 5'-GNNC sites. Monoalkylation occurred at all deoxyguanosines. The sites for both monoalkylation and interstrand cross-linking were similar in nucleosomal and free DNA, and cross-linked DNA was cleanly incorporated into the core particle structure. These findings suggest that the 5S core particle is able to tolerate any structural abnormalities induced by diepoxide cross-linking.
authors.affiliation: Department of Chemistry, Colby College, Waterville, Maine 04901, USA. jtmillar@colby.edu
authors.forename: J T
authors.initials: JT
authors.lastname: Millard
authors.forename: E E
authors.initials: EE
authors.lastname: Wilkes
mesh_terms: D000818:Animals; D001483:Base Sequence; D002645:Chickens; D003432:Cross-Linking Reagents; D004247:DNA / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry*; D008969:Molecular Sequence Data; D012341:RNA, Ribosomal, 5S / Q000737:chemistry; D014981:Xenopus
chemical_list: D003432:Cross-Linking Reagents; D004852:Epoxy Compounds; D012341:RNA, Ribosomal, 5S; C012896:1,2,7,8-diepoxyoctane; C007366:diepoxybutane; D004247:DNA