[The type of interaction of histone H5 wo ith DNA changes significantly at various stages of chromatin condensation].
Histones were covalently bound to DNA by dimethylsulfate-induced crosslinking and DNA-contacting peptides of histone H5, thus modified, were mapped by a combination of peptide cleavage reactions and peptide gel electrophoresis. In the nucleosome, the only strong crosslinking point is His-25 which resides near the ends of nucleosomal DNA. This contact point persists throughout different steps of chromatin condensation--decondensation. In decondensed chromatin, it is supplemented by the contact with DNA of the N-terminus of the histone H5 molecule. The high level of chromatin condensation existing in the nuclei or induced by bivalent cations results in a new and considerably stronger crosslinking point His-62, which is also characteristic for cooperative H5-DNA complexes. This structural change is observed only on oligonucleosomal chains containing no less than 3 contiguous nucleosomes, and is absent in isolated mono- or dinucleosomes. We propose that the formation of the 30-nm chromatin fibre, typical for the nuclei, is accomplished in part by the histone H5-linker DNA cooperative interactions, manifested by strong His-62--linker DNA contact.
Pruss
D V
DV
Ebralidze
K K
KK
Mirzabekov
A D
AD
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002645:Chickens; D002843:Chromatin / Q000378:metabolism* / Q000648:ultrastructure; D004247:DNA / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism / Q000648:ultrastructure; D006657:Histones / Q000378:metabolism*; D046911:Macromolecular Substances; D009707:Nucleosomes / Q000378:metabolism
D002843:Chromatin; D006657:Histones; D046911:Macromolecular Substances; D009707:Nucleosomes; D004247:DNA
Kharakter vzaimodeĭstviia gistona H5 s DNK sushchestvenno meniaetsia na razlichnykh stadiiakh kondensatsii khromatina.