Producción CyT
Artículo
Autoría
OCAMPO, JOSEFINA
;
Hope A Cole
;
Feng Cui
;
Tara L Burke
;
Tatiana Nikitina
;
V Nagarajavel
;
Naoe Kotomura
;
Victor B. Zurkin
;
David J Clark
Fecha
2015
Editorial y Lugar de Edición
OXFORD UNIV PRESS
Revista
NUCLEIC ACIDS RESEARCH,
vol. 44
(pp. 573-581)
OXFORD UNIV PRESS
Resumen
Información suministrada por el agente en
SIGEVA
Eukaryotic chromosomal DNA is assembled into regularly spaced nucleosomes, which play a central role in gene regulation by determining accessibility of control regions. The nucleosome contains approximately 147 bp of DNA wrapped approximately 1.7 times around a central core histone octamer. The linker histone, H1, binds both to the nucleosome, sealing the DNA coils, and to the linker DNA between nucleosomes, directing chromatin folding. Micrococcal nuclease (MNase) digests the linker to yield t...
Eukaryotic chromosomal DNA is assembled into regularly spaced nucleosomes, which play a central role in gene regulation by determining accessibility of control regions. The nucleosome contains approximately 147 bp of DNA wrapped approximately 1.7 times around a central core histone octamer. The linker histone, H1, binds both to the nucleosome, sealing the DNA coils, and to the linker DNA between nucleosomes, directing chromatin folding. Micrococcal nuclease (MNase) digests the linker to yield the chromatosome, containing H1 and about 160 bp, and then converts it to a core particle, containing about 147 bp and no H1. Sequencing of nucleosomal DNA obtained after MNase digestion (MNase- seq) generates genome-wide nucleosome maps that are important for understanding gene regulation. We present an improved MNase-seq method involving simultaneous digestion with exonuclease III, which removes linker DNA. Remarkably, we discovered two novel intermediate particles containing 154 or 161 bp, corresponding to 7 bp protruding from one or both sides of the nucleosome core. These particles are detected in yeast lacking H1 and in H1-depleted mouse chromatin. They can be reconstituted in vitro using purified core histones and DNA. We propose that these "proto-chromatosomes" are fundamental chromatin subunits, which include the H1 binding site and influence nucleosome spacing independently of H1.
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Palabras Clave
proto-chromatosomenucleosome positionChromatin structure