title: Translation initiation factor IF1 is essential for cell viability in Escherichia coli.
abstract: Translation initiation factor IF1 is a highly conserved element of the prokaryotic translational apparatus. It has been demonstrated earlier that the factor stimulates in vitro the initiation phase of protein synthesis. However, no mutation in its gene, infA, has been identified, and a role for IF1 in translation has not been demonstrated in vivo. To elucidate the function of IF1 and determine if the protein is essential for cell growth, the chromosomal copy of infA was disrupted. Cell viability is maintained only when infA is expressed in trans from a plasmid, thereby demonstrating that IF1 is essential for cell growth in Escherichia coli. Cells depleted of IF1 exhibit few polysomes, suggesting that IF1 functions in the initiation phase of protein synthesis.
authors.affiliation: Department of Biological Chemistry, School of Medicine, University of California, Davis 95616.
authors.forename: H S
authors.initials: HS
authors.lastname: Cummings
authors.forename: J W
authors.initials: JW
authors.lastname: Hershey
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development*; D015977:Eukaryotic Initiation Factor-1 / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D005804:Genes, Lethal / Q000235:genetics*; D016254:Mutagenesis, Insertional; D014176:Protein Biosynthesis / Q000235:genetics*
chemical_list: D015977:Eukaryotic Initiation Factor-1