RNA polymerase sigma factor; genes hasR & hasL are 99% similar at the nucleotide level; alternative sigma factor homolog; hasR is one copy of a duplicated gene: hasR/hasL; from Streptomyces ambofaciens; amino acid sequence in first source; GenBank AF050150; DO NOT confuse with HasR protein, a heme receptor
Source
Proc Natl Acad Sci U S A 1998 Nov 24;95(24):14296-301