title: Mutations influencing the frr gene coding for ribosome recycling factor (RRF).
abstract: 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.
authors.affiliation: Department of Microbiology School of Medicine, University of Pennsylvania, USA.
authors.forename: L
authors.initials: L
authors.lastname: Janosi
authors.forename: H
authors.initials: H
authors.lastname: Mori
authors.forename: Y
authors.initials: Y
authors.lastname: Sekine
authors.forename: J
authors.initials: J
authors.lastname: Abragan
authors.forename: R
authors.initials: R
authors.lastname: Janosi
authors.forename: G
authors.initials: G
authors.lastname: Hirokawa
authors.forename: A
authors.initials: A
authors.lastname: Kaji
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D005798:Genes, Bacterial; D007438:Introns; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012269:Ribosomal Proteins; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism; D013489:Suppression, Genetic; D013696:Temperature; D013816:Thermodynamics
chemical_list: D011506:Proteins; D011994:Recombinant Proteins; D012269:Ribosomal Proteins; C087267:ribosome releasing factor