Mechanism of chromatin remodeling and recovery during passage of RNA polymerase II.
Transcription of eukaryotic genes by RNA polymerase II (Pol II) is typically accompanied by nucleosome survival and minimal exchange of histones H3 and H4. The mechanism of nucleosome survival and recovery of chromatin structure remains obscure. Here we show how transcription through chromatin by Pol II is uniquely coupled with nucleosome survival. Structural modeling and functional analysis of the intermediates of transcription through a nucleosome indicated that when Pol II approaches an area of strong DNA-histone interactions, a small intranucleosomal DNA loop (zero-size or Ø-loop) containing transcribing enzyme is formed. During formation of the Ø-loop, the recovery of DNA-histone interactions behind Pol II is tightly coupled with their disruption ahead of the enzyme. This coupling is a distinct feature of the Pol II-type mechanism that allows further transcription through the nucleosome, prevents nucleosome translocation and minimizes displacement of H3 and H4 histones from DNA during enzyme passage.
Kulaeva
Olga I
OI
Department of Pharmacology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, New Jersey, USA.
Gaykalova
Daria A
DA
Pestov
Nikolai A
NA
Golovastov
Viktor V
VV
Vassylyev
Dmitry G
DG
Artsimovitch
Irina
I
Studitsky
Vasily M
VM
D042002:Chromatin Assembly and Disassembly; D004247:DNA / Q000378:metabolism*; D004926:Escherichia coli / Q000502:physiology; D029968:Escherichia coli Proteins / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism*; D014158:Transcription, Genetic
D029968:Escherichia coli Proteins; D006657:Histones; D009707:Nucleosomes; D004247:DNA; D012319:RNA Polymerase II