The upstream sequences of the HSP82 and HSC82 genes of Saccharomyces cerevisiae: regulatory elements and nucleosome positioning motifs.

We present the upstream sequences of HSP82 and HSC82, two closely related, but differentially regulated, heat-shock genes of Saccharomyces cerevisiae. Several dozen potential regulatory elements are identified within each upstream region; interestingly, only a few are conserved between the two genes. These include a consensus heat-shock element, an upstream repressor element, and a consensus TATA element. A search for motifs known actively to position nucleosomes in vitro revealed that such sequences are three- to seven-fold enriched within each promoter; a comparable enrichment is seen near the 3' end of each transcription unit. Located approximately 1100 bp upstream of HSC82 is an open reading frame (ORF) of 255 amino acids; approximately 800 bp upstream of HSP82 is an ORF of 132 amino acids. The latter ORF contains several conserved ankyrin motifs and appears to be expressed under normal growth conditions. Finally, we show by clamped homogeneous electric field gel electrophoresis that the two genetic loci map to different chromosomes: HSP82 to chromosome XVI and HSC82 to chromosome XIII. The sequences have been deposited in the GenBank database under Accession Numbers U20323 and U20349.