Histone N-terminal tails interfere with nucleosome traversal by RNA polymerase II.
We determined the effect of the N-terminal histone tails on nucleosome traversal by yeast and human RNA polymerase II (pol II). Removal of H2A/H2B tails, H3/H4 tails, or all tails increased complete traversal of the nucleosome by human pol II, although the increase varied considerably depending on the template and on which tails were removed. Human pol II achieved >80% traversal of one nucleosomal template lacking the H2A/H2B tails, but even in those reactions, the transcript elongation rate was lower than the rate on pure DNA templates. For yeast pol II, transcription proceeded much farther into the nucleosome in the absence of tails, but complete read-through was not substantially increased by tail removal. Transcription factor IIS provided roughly the same level of read-through stimulation for transcript elongation in the presence or absence of tails. FACT also stimulated elongation on nucleosomal templates, and this effect was similar regardless of the presence of tails. For both polymerases, removal of the H2A/H2B tails reduced pausing throughout the nucleosome, suggesting that histone tails affect a common step at most points during nucleosome traversal. We conclude that histone tails provide a significant part of the nucleosomal barrier to pol II transcript elongation.
Ujvári
Andrea
A
Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
Hsieh
Fu-Kai
FK
Luse
Susan W
SW
Studitsky
Vasily M
VM
Luse
Donal S
DS
D000818:Animals; D002645:Chickens; D002843:Chromatin / Q000737:chemistry; D004912:Erythrocytes / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry; D006657:Histones / Q000737:chemistry*; D006801:Humans; D009707:Nucleosomes / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D013997:Time Factors; D014158:Transcription, Genetic; D014981:Xenopus
D002843:Chromatin; D005656:Fungal Proteins; D006657:Histones; D009707:Nucleosomes; D011994:Recombinant Proteins; D012319:RNA Polymerase II