Long-range effects of histone point mutations on DNA remodeling revealed from computational analyses of SIN-mutant nucleosome structures.

ABSTRACT: The packaging of DNA into nucleosomes impedes the binding and access of molecules involved in its processing. The SWI/SNF multi-protein assembly, found in yeast, is one of many regulatory factors that stimulate the remodeling of DNA required for its transcription. Amino-acid point mutations in histones H3 or H4 partially bypass the requirement of the SWI/SNF complex in this system. The mechanisms underlying the observed remodeling, however, are difficult to discern from the crystal structures of nucleosomes bearing these so-called SIN (SWI/SNF INdependent) mutations. Here, we report detailed analyses of the conformations and interactions of the histones and DNA in these assemblies. We find that the loss of direct protein-DNA contacts near point-mutation sites, reported previously, is coupl

SUBMITTER: Xu F 

PROVIDER: S-EPMC2978337 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature