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Histone H1 binding is inhibited by histone variant H3.3
Author(s) -
Braunschweig Ulrich,
Hogan Greg J,
Pagie Ludo,
van Steensel Bas
Publication year - 2009
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2009.301
Subject(s) - biology , histone h1 , histone h3 , histone , histone code , genetics , histone methyltransferase , histone h2a , microbiology and biotechnology , nucleosome , dna
Linker histones are involved in the formation of higher‐order chromatin structure and the regulation of specific genes, yet it remains unclear what their principal binding determinants are. We generated a genome‐wide high‐resolution binding map for linker histone H1 in Drosophila cells, using DamID. H1 binds at similar levels across much of the genome, both in classic euchromatin and heterochromatin. Strikingly, there are pronounced dips of low H1 occupancy around transcription start sites for active genes and at many distant cis ‐regulatory sites. H1 dips are not due to lack of nucleosomes; rather, all regions with low binding of H1 show enrichment of the histone variant H3.3. Knockdown of H3.3 causes H1 levels to increase at these sites, with a concomitant increase in nucleosome repeat length. These changes are independent of transcriptional changes. Our results show that the H3.3 protein counteracts association of H1, providing a mechanism to keep diverse genomic sites in an open chromatin conformation.