Characterization of cis-acting elements residing in the chitinase promoter of Bacillus pumilus SG2

World J Microbiol Biotechnol. 2014 May;30(5):1491-9. doi: 10.1007/s11274-013-1569-9. Epub 2013 Dec 1.

Abstract

Bacillus pumilus SG2 is a chitinolytic bacterium that produces two chitinases, namely ChiS and ChiL. The chiS and chiL genes are consecutively expressed under a common promoter. Regulation of the chiS and chiL genes is under the control of carbon catabolite repression (CCR) in B. pumilus. This study aimed to investigate the cis-acting elements of the chitinase promoter. For this purpose, we transferred the chiS gene along with its specific promoter to Bacillus subtilis as a host. Primer extension analysis revealed two transcription start sites located 287 and 65 bp upstream of the chiS start codon. The distal promoter was highly compatible with the consensus sequence of the σ(A)-type promoters in B. subtilis, whereas the proximal promoter sequence showed less similarity to the σ(A)-type consensus sequence. A catabolite responsive element (cre), which is required for CCR in Bacillus species, was found to be 136 to 123 bp upstream of the chiS start codon. Interestingly, this cre site was located upstream of the -35 of the proximal promoter and downstream of the distal promoter. Deletion of this cre site sequence rendered the chiS expression constitutive.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus / classification
  • Bacillus / enzymology*
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Base Sequence
  • Catabolite Repression*
  • Chitin / metabolism
  • Chitinases / genetics*
  • Chitinases / metabolism
  • DNA, Bacterial / analysis
  • Gene Expression Regulation, Bacterial
  • Glucose / metabolism
  • Molecular Sequence Data
  • Promoter Regions, Genetic
  • Repetitive Sequences, Nucleic Acid
  • Transcription Initiation Site*
  • Transformation, Bacterial

Substances

  • Bacterial Proteins
  • DNA, Bacterial
  • Chitin
  • Chitinases
  • Glucose