title: Cold-sensitive growth and decreased GTP-hydrolytic activity from substitution of Pro17 for Val in Era, an essential Escherichia coli GTPase.
abstract: A substitution mutation of Pro17 by Val (P17V) was constructed in the guanine nucleotide binding domain of Era, an essential protein in Escherichia coli. The mutation is analogous to the oncogenic activating allele at position 12 in the GTP-binding domain of p21ras. The phenotype of this mutant was analysed in a strain which exclusively expressed the mutant protein (Era-V17) in null allele chromosomal background (era1: :kan). The strain was found to be cold-sensitive for growth. Mutant Era-V17 purified from the strain was cold-sensitive for GTP-hydrolytic activity, suggesting that the GTPase activity of Era is required for cell growth since the P17V mutation resulted in both cold-sensitive growth of cells and cold-labile GTPase activity of the purified protein.
authors.affiliation: Department of Biochemistry, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Rutgers, Piscataway 08854.
authors.forename: C G
authors.initials: CG
authors.lastname: Lerner
authors.forename: P
authors.initials: P
authors.lastname: Sood
authors.forename: J
authors.initials: J
authors.lastname: Ahnn
authors.forename: M
authors.initials: M
authors.lastname: Inouye
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003080:Cold Temperature; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development*; D029968:Escherichia coli Proteins; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D016297:Mutagenesis, Site-Directed / Q000235:genetics; D010641:Phenotype; D011392:Proline / Q000235:genetics / Q000502:physiology*; D016601:RNA-Binding Proteins; D014633:Valine / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D016601:RNA-Binding Proteins; C068027:era protein, E coli; D011392:Proline; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D014633:Valine