Cloning and expression of the ccpA gene encoding catabolite control protein from Thermoactinomyces sp. E79

Abstract

The gene ccpA encoding the catabolite control protein A (CcpA) of Thermoactinomyces sp. E79 has been cloned and characterized. Nucleotide sequence analysis of the CcpA clone showed that the cloned fragment contained the full structural gene for a protein of 346 amino acids. The predicted amino acid sequence shows similarity to the transcriptional regulators of the LacI-GaIR family; a highly conserved helix-turn-helix motif, which might bind to DNA, was identified through comparison with regulator proteins in this family. The highest sequence identity was obtained when it was compared with the CcpA of Bacillus subtilis (60%) or Bacillus megaterium (60%). The expression of ccpA in Thermoactinomyces sp. E79 was dependent on glucose, which is contrast to the cases of B. subtilis, B. megaterium and S. xylosus. The complementation experiment with the B. megaterium ccpA mutant indicated that the cloned gene was a ccpA.