Cloning and sequencing of the hrcA gene of Bacillus stearothermophilus.

We report on cloning and sequencing of a 2.0-kb PCR fragment of chromosomal DNA from thermophilic Bacillus stearothermophilus carrying the complete hrcA gene. In addition, this amplicon contains the 3' end of an open reading frame exhibiting significant homology to the hemN gene of Bacillus subtilis (Bs) and other bacterial species. The hrcA gene could complement an Bs hrcA deletion mutant by repressing expression of class I heat shock (HS) genes. Furthermore, we could show that the HrcA protein derived from the thermophilic microorganism responds to HS in a similar way as reported for the Bs HrcA protein.