GcvA interacts with both the alpha and sigma subunits of RNA polymerase to activate the Escherichia coli gcvB gene and the gcvTHP operon

FEMS Microbiol Lett. 2005 Jan 15;242(2):333-8. doi: 10.1016/j.femsle.2004.11.027.


The glycine cleavage enzyme system in Escherichia coli provides one-carbon units for cellular methylation reactions. The gcvB gene encodes two small RNAs that in turn regulate other genes. The GcvA protein is required for expression of both the gcvTHP (P(gcvT)) and gcvB (P(gcvB)) promoters. However, the architectures of the two promoters are different, with the P(gcvT) promoter representing a class III activator-dependent promoter and the P(gcvB) promoter representing a class II activator-dependent promoter. The RNA polymerase holoenzyme was examined for its role in transcription activation of the gcvTHP operon and the gcvB gene by the GcvA protein. The results suggest that GcvA interacts with the RNA polymerase alpha subunit for activation of the gcvTHP operon and interacts with the RNA polymerase sigma subunit for activation of the gcvB gene.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Oxidoreductases / genetics*
  • Carrier Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • DNA-Binding Proteins / physiology*
  • DNA-Directed RNA Polymerases / genetics
  • DNA-Directed RNA Polymerases / metabolism*
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Escherichia coli Proteins / metabolism
  • Escherichia coli Proteins / physiology*
  • Gene Expression Regulation
  • Glycine / metabolism
  • Multienzyme Complexes / genetics*
  • Operon / physiology*
  • Promoter Regions, Genetic
  • Transcription Factors / metabolism
  • Transcription Factors / physiology*
  • Transferases / genetics*


  • Carrier Proteins
  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • GcvA protein, E coli
  • Multienzyme Complexes
  • Transcription Factors
  • glycine cleavage system
  • Amino Acid Oxidoreductases
  • Transferases
  • DNA-Directed RNA Polymerases
  • Glycine