In order to define the mechanisms responsible for the regulated expression of a human 90-kDa heat shock protein (HSP90) gene, we have determined the complete genomic sequence of the gene encoding HSP90 beta, including 1102 base pairs upstream of the transcription initiation site. This gene consists of 12 exons and 11 introns. The exons range in size from 99 to 396 base pairs and the introns range from 91 to 1433 base pairs. Analysis of the 5' promoter region revealed TATA and CAAT consensus sequences. Additionally, Sp1 factor binding sites and presumptive heat shock element consensus sequences were found surrounding the transcription initiation site. Three out of the six identified potential heat shock elements reside within the first intron. The ability of the promoter region to respond to heat shock was examined by constructing a plasmid containing the 5' end of the HSP90 beta gene driving a neomycin phosphotransferase reporter gene. This plasmid was used to stably transform human K562 erythroleukemia cells. With heat shock, the abundance of HSP-neo transcripts increased, demonstrating that the promoter region of this gene contains the cis-acting DNA elements required for the heat shock response.