Abstract
The genes for hrdA and hrdD were isolated from a streptomycin-producing Streptomyces griseus 2247, using a probe for the ‘rpoD box’. The nucleotide sequence of the hrdA region revealed the presence of two open reading frames (ORF). One of them consisting of 1083 bp encodes a HrdA protein of 363 amino acids (Mr 40574). The predicted protein (Mr 69212) of the other ORF in the hrdA region is highly homologous to ATP-dependent transporters. The nucleotide sequence of the hrdD region was also determined. The ORF of 999 bp for hrdD encodes a putative protein of 333 amino acids with a Mr 37196 (HrdD). The deduced amino acid sequences of HrdA and HrdD possess the subregions which are conserved in the rpoD (σ70) family of eubacteria. These hrd genes of S. griseus encode the group 2 σ factors of rpoD family.
