Determinants of mer Promoter Activity from Pseudomonas aeruginosa

Genes (Basel). 2024 Apr 13;15(4):490. doi: 10.3390/genes15040490.

Abstract

Since the MerR family is known for its special regulatory mechanism, we aimed to explore which factors determine the expression activity of the mer promoter. The Tn501/Tn21 mer promoter contains an abnormally long spacer (19 bp) between the -35 and -10 elements, which is essential for the unique DNA distortion mechanism. To further understand the role of base sequences in the mer promoter spacer, this study systematically engineered a series of mutant derivatives and used luminescent and fluorescent reporter genes to investigate the expression activity of these derivatives. The results reveal that the expression activity of the mer promoter is synergistically modulated by the spacer length (17 bp is optimal) and the region upstream of -10 (especially -13G). The spacing is regulated by MerR transcription factors through symmetrical sequences, and -13G presumably functions through interaction with the RNA polymerase sigma-70 subunit.

Keywords: expression activity; guanine; mer promoter; position −13; spacer length; synergistic regulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins* / genetics
  • DNA Transposable Elements / genetics
  • DNA-Directed RNA Polymerases / genetics
  • DNA-Directed RNA Polymerases / metabolism
  • Gene Expression Regulation, Bacterial*
  • Promoter Regions, Genetic*
  • Pseudomonas aeruginosa* / genetics
  • Sigma Factor* / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Bacterial Proteins
  • Sigma Factor
  • Transcription Factors
  • DNA-Directed RNA Polymerases
  • DNA Transposable Elements
  • RNA polymerase sigma 70