Mutations influencing the frr gene coding for ribosome recycling factor (RRF)

J Mol Biol. 2000 Jan 28;295(4):815-29. doi: 10.1006/jmbi.1999.3401.


A total of 52 null, six reversion, and five silent mutations of frr (the gene encoding for ribosome recycling factor (RRF)) of Escherichia coli are discussed along with 12 temperature-sensitive (ts) mutations and 14 intergenic suppressor strains of ts RRF. The null mutations were classified into six different categories. A computer-based secondary structure analysis showed three domains; domain A which has the N-terminal helix, domain B which contains coil, alpha-helix and beta-strand structure, and domain C which is a C-terminal helix. The ts mutations fell into domains A and C but not in domain B. More than a half of the null mutations fell into domain B while the silent mutations fell outside domain B. Substitution of Arg132 in domain C by other amino acids was observed among five independently isolated null mutants. It is suggested that domain B is important for maintaining the RRF structure, while the region including Arg132 is one of the active sites. A total of 14 intergenic suppressor strains of ts RRF were grouped into four categories, depending on which temperature-sensitive alleles were suppressed.

MeSH terms

  • Amino Acid Sequence
  • Amino Acid Substitution
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism*
  • Genes, Bacterial*
  • Introns
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Proteins / chemistry*
  • Proteins / genetics
  • Proteins / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Ribosomal Proteins
  • Ribosomes / genetics
  • Ribosomes / metabolism
  • Suppression, Genetic
  • Temperature
  • Thermodynamics


  • Proteins
  • Recombinant Proteins
  • Ribosomal Proteins
  • ribosome releasing factor