The site of binding of linker histone to the nucleosome does not depend upon the amino termini of core histones

Using nucleosomes reconstituted on a defined sequence of DNA, we have inves tigated the question as to whether the N-terminal tails of core histones pl ay a role in determining the site of binding of a linker histone. Reconstit utes used histone cores of three types: intact, lacking the N-terminal H3 t ails, or lacking all tails. In each case the same, single defined position for the histone core was observed, using high-resolution mapping. The affin ity for binding of linker histone H1 degrees was highest for the intact cor es, lowest for the tailless cores. However, the location of the linker hist one, as judged by micrococcal nuclease protection, was exactly the same in each-case, an asymmetric site of about 17 bp to one side of the core partic le DNA. (C) 1999 Societe francaise de biochimie et biologie moleculaire / E ditions scientifiques et medicales Elsevier SAS.