Folding of chromatin in the presence of heterogeneous histone H1 binding to nucleosomes.
We have reconstituted oligonucleosome complexes containing histone H1 starting from a synthetic DNA template, consisting of 12 tandemly arranged 208-base pair fragments of the 5 S rRNA gene, purified HeLa histone octamers, and histone H1. A ratio of histone H1 per histone octamer used in the reconstitution (0.8-0.9 mol of histone H1/mol of histone octamer) similar to that observed in vivo was used. The reconstituted chromatin complexes exhibit a salt-dependent folding, which is almost indistinguishable from that exhibited by chromatin fragments obtained from nuclease digestion of native chromatin. The folding of this reconstituted chromatin complex seems to be rather independent of the symmetrical or asymmetrical position occupied by H1 in the individual nucleosomes. Binding of histone H1 to the oligonucleosome complexes, under the stoichiometric binding conditions used, had no inhibitory effect on the transcriptional potential of these complexes.
Howe
L
L
Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada.
Iskandar
M
M
Ausió
J
J
D000818:Animals; D002843:Chromatin / Q000648:ultrastructure*; D004275:DNA, Ribosomal; D006367:HeLa Cells; D006657:Histones / Q000737:chemistry*; D006801:Humans; D015636:Magnesium Chloride / Q000494:pharmacology; D009994:Osmolar Concentration; D012320:RNA Polymerase III / Q000378:metabolism; D012341:RNA, Ribosomal, 5S; D012617:Sea Urchins; D012965:Sodium Chloride; D014158:Transcription, Genetic; D014461:Ultracentrifugation
D002843:Chromatin; D004275:DNA, Ribosomal; D006657:Histones; D012341:RNA, Ribosomal, 5S; D015636:Magnesium Chloride; D012965:Sodium Chloride; D012320:RNA Polymerase III