title: Organization of spacer DNA in chromatin.
abstract: Detailed analysis of the DNA fragment patterns produced by DNase I digestion of yeast, HeLa, and chicken erythrocyte nuclei reveals surprising features of nucleosome phasing. First, the spacer regions in phased yeast chromatin must be of lengths (10m + 5) base pairs, where m = 0, 1, 2,.... This feature is not seen in parallel studies of chicken erythrocyte chromatin. The 5-base pair increment in the yeast spacer imposes interesting restraints on the higher order structure of yeast chromatin. Second, we have been able to simulate the DNase I cutting patterns and get good agreement with the observed yeast patterns. Third, three different chromatins show a long range periodicity in the DNase I digest pattern, with a period half that of the staphylococcal nuclease repeat. These results suggest that the amount of chromatin observed in discrete extended-ladder bands is a minimum estimate of phasing and in fact phasing may be a more general feature.
mesh_terms: D000818:Animals; D002645:Chickens; D002843:Chromatin / Q000648:ultrastructure*; D004247:DNA / Q000235:genetics*; D003851:Deoxyribonucleases / Q000378:metabolism*; D004912:Erythrocytes / Q000648:ultrastructure; D006367:HeLa Cells; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae / Q000648:ultrastructure
chemical_list: D002843:Chromatin; D004247:DNA; D003851:Deoxyribonucleases