title: High resolution positioning of intron ends on the nucleosomes.
abstract: High resolution sequence-directed nucleosome mapping is applied to 36,000 sequences containing splice junctions, from five different species. As it has been also shown in previous studies, the junctions are found to be preferentially located within nucleosomes. Moreover, the orientation of guanine residues at the GT- and AG-ends of introns within the nucleosomes is such that the guanines are positioned nearest to the surface of histone octamers, 3 and 4 bases upstream from the local DNA pseudo-dyads passing through minor grooves oriented outwards. Since the guanine residues are the most vulnerable to spontaneous damage within the cell (primarily, depurination and oxidation) such positioning of the splice junctions minimizes the damage that is caused by free radicals and highly reactive metabolites.
authors.affiliation: Department of Functional Genomics and Proteomics, CEITEC and Faculty of Science, Masaryk University, Kotlarska 2, CZ-61137 Brno, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Hapala
authors.forename: Edward N
authors.initials: EN
authors.lastname: Trifonov
mesh_terms: D000818:Animals; D001483:Base Sequence; D002645:Chickens / Q000235:genetics; D004285:Dogs; D006657:Histones / Q000378:metabolism; D006801:Humans; D007438:Introns; D051379:Mice; D008969:Molecular Sequence Data; D009707:Nucleosomes / Q000235:genetics*; D015027:Zebrafish / Q000235:genetics
chemical_list: D006657:Histones; D009707:Nucleosomes