H3 Cys-110 is in close proximity to the C-terminal regions of H2B and H4 in a nucleosome core with an altered internal arrangement of histones.
A particle obtained by nuclease digestion of nucleohistone complexes prepared by direct mixing of histones with DNA in 0.15 M NaCl was indistinguishable by composition and physical properties from nucleosome cores prepared under the same conditions from nucleohistone preannealed in 0.6 M NaCl. We show here that different photo-cross-links form when these particles are prepared from H3 labeled with photoaffinity reagents on the unique histone H3 cysteine. H3-H3 histone dimers were dominant when the particles were prepared by dilution of the nucleohistone from 0.6 M NaCl while H3-H2B and H3-H4 histone dimers were prominent if the nucleohistone complex was prepared directly in 0.15 M NaCl. Peptide mapping of the novel H3-H4 and H3-H2B dimers showed that Cys-110 of histone H3 is cross-linked to the 18 amino acid C-terminal end of H4 or to the 66 amino acid C-terminal half of H2B.
Kahr
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Department of Biochemistry, University of Toronto, Ontario, Canada.
Lewis
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Pulleyblank
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D000345:Affinity Labels; D000818:Animals; D002645:Chickens; D003432:Cross-Linking Reagents / Q000493:pharmacokinetics; D003488:Cyanogen Bromide / Q000494:pharmacology; D003545:Cysteine / Q000032:analysis*; D004247:DNA / Q000378:metabolism; D003850:Deoxyribonuclease I; D004912:Erythrocytes / Q000032:analysis*; D006657:Histones / Q000032:analysis*; D009707:Nucleosomes / Q000032:analysis* / Q000187:drug effects; D010449:Peptide Mapping; D011487:Protein Conformation
D000345:Affinity Labels; D003432:Cross-Linking Reagents; D006657:Histones; D009707:Nucleosomes; D004247:DNA; D003850:Deoxyribonuclease I; D003545:Cysteine; D003488:Cyanogen Bromide