GCN5, A YEAST TRANSCRIPTIONAL COACTIVATOR, INDUCES CHROMATIN RECONFIGURATION OF HIS3 PROMOTER IN-VIVO

Gcn5p, the nuclear histone acetyltransferase (KAT A), is a component o f the multiprotein adaptor complex, ADA. Its role as a transcriptional coactivator is required for full induction of most of the genes regul ated by GCN4, In this study we present experimental evidence demonstra ting that, during gene activation, the nuclease sensitive region of HI S3 promoter, harbouring the poly (dA;dT) and the GCN4 binding site, is invaded by nucleosomes in a gcn5 disrupted strain. These data demonst rate, for the first time, that Gcn5p affects directly the chromatin or ganization of a chromosomal gene during its transcriptional activation . (C) 1998 Academic Press.