title: Temperature-sensitive lethal mutant of era, a G protein in Escherichia coli.
abstract: The era gene of Escherichia coli encodes a GTP-binding protein which has similarities to elongation factor Tu and the Saccharomyces cerevisiae RAS protein. To investigate its function, mutations affecting era were isolated. A mini-Tn10 insertion, which truncated 22 amino acids from the COOH end of Era, did not affect cell growth. By using this mini-Tn10 insert as a coselectable marker, a temperature-sensitive lethal era mutant was isolated by localized mutagenesis using P1 phage transduction. A single-base G to A change was found at position 23, causing a tyrosine residue to be substituted for the cysteine residue at position 8 (era-770), in addition to the COOH-terminal mini-Tn10 disruption. Both alterations were necessary for the temperature-sensitive phenotype. Purified Era-770 mutant protein exhibited reduced binding to GTP compared with that of the wild-type Era protein.
authors.affiliation: Department of Tumor Biology, University of Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Inada
authors.forename: K
authors.initials: K
authors.lastname: Kawakami
authors.forename: S M
authors.initials: SM
authors.lastname: Chen
authors.forename: H E
authors.initials: HE
authors.lastname: Takiff
authors.forename: D L
authors.initials: DL
authors.lastname: Court
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamura
mesh_terms: D000595:Amino Acid Sequence; D010582:Bacteriophage lambda / Q000235:genetics; D001483:Base Sequence; D002876:Chromosomes, Bacterial; D004926:Escherichia coli / Q000235:genetics*; D019204:GTP-Binding Proteins / Q000235:genetics*; D005796:Genes; D005798:Genes, Bacterial; D005804:Genes, Lethal; D005816:Genetic Complementation Test; D005838:Genotype; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010957:Plasmids; D015183:Restriction Mapping; D013696:Temperature; D014161:Transduction, Genetic
chemical_list: D019204:GTP-Binding Proteins