Orientation of functional activating regions in the Escherichia coli CRP protein during transcription activation at class II promoters

Nucleic Acids Res. 1996 Mar 15;24(6):1112-8. doi: 10.1093/nar/24.6.1112.

Abstract

At class II CRP-dependent promoters the DNA site for CRP overlaps the DNA site for RNA polymerase, covering the -35 region. Transcription activation at class II CRP- dependent promoters requires a contact between an activating region in the upstream subunit of the bound CRP dimer and a contact site in the C-terminal domain of the alpha-subunit of RNA polymerase. Transcription activation is suppressed by amino acid substitutions in the activating region, but activation can be restored by second site substitutions at K52 or E96. These substitutions identify two separate regions on the surface of CRP that appear to be able to interact with RNA polymerase specifically at class II promoters. Using the method of 'oriented heterodimers' we show that these alternative activating regions are functional in the downstream subunit of the bound CRP dimer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Binding Sites / genetics
  • Carrier Proteins
  • Cyclic AMP Receptor Protein / chemistry
  • Cyclic AMP Receptor Protein / genetics*
  • Cyclic AMP Receptor Protein / metabolism*
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • DNA, Bacterial / metabolism
  • DNA-Directed RNA Polymerases / chemistry
  • DNA-Directed RNA Polymerases / metabolism
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism*
  • Genes, Bacterial
  • Models, Molecular
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Promoter Regions, Genetic*
  • Protein Conformation
  • Transcriptional Activation

Substances

  • Bacterial Proteins
  • Carrier Proteins
  • Cyclic AMP Receptor Protein
  • DNA, Bacterial
  • DNA-Directed RNA Polymerases