Novel regulation targets of the metal-response BasS-BasR two-component system of Escherichia coli

Microbiology (Reading). 2012 Jun;158(Pt 6):1482-1492. doi: 10.1099/mic.0.057745-0. Epub 2012 Mar 22.

Abstract

The BasS-BasR two-component system is known as an iron- and zinc-sensing transcription regulator in Escherichia coli, but so far only a few genes have been identified to be under the direct control of phosphorylated BasR. Using Genomic SELEX (systematic evolution of ligands by exponential enrichment) screening, we have identified a total of at least 38 binding sites of phosphorylated BasR on the E. coli genome, and based on the BasR-binding sites, have predicted more than 20 novel targets of regulation. By DNase I footprint analysis for high-affinity BasR-binding sites, a direct repeat of a TTAAnnTT sequence was identified as the BasR box. Transcription regulation in vivo of the target genes was confirmed after Northern blot analysis of target gene mRNAs from both wild-type E. coli and an otherwise isogenic basR deletion mutant. The BasR regulon can be classified into three groups of genes: group 1 includes the genes for the formation and modification of membrane structure; group 2 includes genes for modulation of membrane functions; and group 3 includes genes for stress-response cell functions, including csgD, the master regulator of biofilm formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • Escherichia coli / chemistry
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / chemistry
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Gene Expression Regulation, Bacterial*
  • Metals / metabolism
  • Molecular Sequence Data
  • Protein Binding
  • Transcription, Genetic

Substances

  • Escherichia coli Proteins
  • Metals