Chromatin assembly on replicating DNA in vitro.
Replicating single-stranded DNA is preferentially assembled into chromatin in Xenopus egg extracts relative to non-replicating double-stranded DNA. We have examined the molecular basis of this phenomenon. Single-stranded DNA itself is not a favored template for nucleosome assembly in comparison to double-stranded DNA. Complementary strand synthesis is required for the rapid assembly of nucleosomes. We present evidence that the assembly of chromatin on replicating DNA is a two step phenomenon. The first step involves the replication of DNA and the assembly of an intermediate structure, the second step involves the sequestration of histones H2A/H2B onto DNA. Histones H2A/H2B are preferentially sequestered onto replicated DNA in comparison to non-replicated DNA incubated in the extract.
Almouzni
G
G
Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892.
Clark
D J
DJ
Méchali
M
M
Wolffe
A P
AP
D000818:Animals; D002843:Chromatin / Q000378:metabolism*; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D007700:Kinetics; D008836:Micrococcal Nuclease / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism / Q000648:ultrastructure*; D013379:Substrate Specificity; D014982:Xenopus laevis
D002843:Chromatin; D004277:DNA, Single-Stranded; D006657:Histones; D009707:Nucleosomes; D008836:Micrococcal Nuclease