DNA-Binding Protein Involved in the Regulation of Chitinase Production inStreptomyces lividans

A protein that binds specifically to the promoter region of chiA was purified from the cell lysate of Streptomyces lividans by using an affinity purification method. Determining the amino-terminal amino acid sequence of the purified protein led to cloning of a gene (cpb1) encoding the chitinase promoter-binding protein, Cpb1. The deduced amino acid sequence of Cpb1 showed significant similarity to the sequences of a group of hypothetical proteins of S. coelicolor that have been revealed by the genome project, and the amino-terminal region of Cpb1 showed similarity to the DNA-binding domains of several transcription factors. The Cpb1 proteins expressed in S. lividans or Escherichia coli showed specific binding activity to the chiA promoter. The disruption of cpb1 resulted in partial relief of the glucose repression of chitinase production, indicating that cpb1 took part in the regulation of chitinase expression in S. lividans.