Histone variant H2A.Z is deposited near transcription start sites by the chromatin remodeler SWR1 and seems to be removed by RNA polymerase II at an early stage of transcription elongation.
In the model plant Arabidopsis thaliana genome dynamic exchanges of histone variants control the organization of histone modifications into chromatin states, acting as molecular landmarks.
The transcription machinery is required for the disassembly of the promoter-proximal H2A.Z nucleosome, contributing to the constitutive histone turnover at yeast promoters.
Specific elements of the canonical nucleosome are recognized by the multi-component SWR1 chromatin remodeler for ATP-dependent replacement of H2A-H2B dimers with H2A.Z-H2B.
Direct observation of RNA Polymerase II transcription through a single nucleosome at near basepair resolution suggests a mechanism for selective control of gene expression.
An in vivo disulfide crosslinking assay shows preferential disassembly of nucleosomes with two H2A.Z histones by transcription machinery in yeast and conjugation to one or two ubiquitin moieties in human cells.