Expression and regulation of the RepA protein of the RepFIB replicon from plasmid P307

J Bacteriol. 1992 Dec;174(23):7533-41. doi: 10.1128/jb.174.23.7533-7541.1992.


The control of RepFIB replication appears to rely on the interaction between an initiator protein (RepA) and two sets of DNA repeat elements located on either side of the repA gene. Limited N-terminal sequence information obtained from a RepA:beta-galactosidase fusion protein indicates that although the first residue of RepA is methionine, the initiation of translation of RepA occurs from a CTG codon rather than from the predicted GTG codon located further downstream. Overexpressed RepA in trans is capable of repressing a repA:lacZ fusion plasmid in which the expression of the fusion protein is under the control of the repA promoter. The repA promoter has been located functionally by testing a series of repA:lacZ fusion plasmids. Both in vivo genetic tests and in vitro DNA-binding studies indicate that repA autoregulation can be achieved by RepA binding to one or more repeat elements which overlap the repA promoter sequence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / biosynthesis*
  • Bacterial Proteins / genetics
  • Base Sequence
  • Codon
  • DNA Helicases*
  • DNA Replication / genetics*
  • DNA, Bacterial / metabolism
  • DNA-Binding Proteins / metabolism
  • Enzyme Induction / drug effects
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Gene Expression Regulation, Bacterial*
  • Isopropyl Thiogalactoside / pharmacology
  • Molecular Sequence Data
  • Peptide Chain Initiation, Translational
  • Plasmids / genetics*
  • Promoter Regions, Genetic / genetics
  • Proteins*
  • Recombinant Fusion Proteins
  • Replicon / genetics*
  • Trans-Activators*
  • beta-Galactosidase / biosynthesis
  • beta-Galactosidase / genetics


  • Bacterial Proteins
  • Codon
  • DNA, Bacterial
  • DNA-Binding Proteins
  • Proteins
  • Recombinant Fusion Proteins
  • Trans-Activators
  • replication initiator protein
  • Isopropyl Thiogalactoside
  • beta-Galactosidase
  • DNA Helicases