The N tails of histones H3 and H4 adopt a highly structured conformation in the nucleosome.
The histone N tails correspond to conserved amino acid sequences that are peripherally located in the nucleosome and undergo a variety of post-synthetic modifications during cell cycle. These N tails have been recently recognized as directly interacting with transcription-related proteins. We show here, based on circular dichroic evidence, that the N tails of both tetrameric histones H3 and H4 are highly organized as DNA-bound polypeptide segments in the nucleosome core particle, with about half of their residues, taken together, being alpha-helical. In contrast, the N tails of both dimeric histones H2A and H2B are found essentially in a random-coil conformation. The implications of these findings on nucleosome structure and recognition are discussed.
Banères
J L
JL
UPRESA CNRS 5074, Chimie Biomoléculaire et Interactions Biologiques, Faculté de Pharmacie, 34060 Montpellier, Cedex 2, France.
Martin
A
A
Parello
J
J
D000818:Animals; D001665:Binding Sites; D002942:Circular Dichroism; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D006657:Histones / Q000737:chemistry* / Q000378:metabolism; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000737:chemistry*; D011487:Protein Conformation; D051381:Rats; D014357:Trypsin / Q000378:metabolism
D006657:Histones; D009707:Nucleosomes; D004247:DNA; D014357:Trypsin; D003546:Cysteine Endopeptidases; C019913:clostripain