title: Genome-wide screen for Escherichia coli genes involved in repressing cell-to-cell transfer of non-conjugative plasmids.
abstract: Acquiring new genetic traits by lateral gene transfer is a bacterial strategy for environment adaptation. We previously showed that Escherichia coli could laterally transmit non-conjugative plasmids in co-cultures containing strains with and without the plasmid. In this study, using the Keio collection, a comprehensive library of E. coli knock-out mutants for non-essential genes, we screened for genes responsible for repressing cell-to-cell plasmid transfer in recipient cells. By stepwise screening, we identified 55 'transfer-up' mutants that exhibited approximately 2- to 30-fold increased activities. We confirmed plasmid acquisition by these 'up' mutants and revealed that there were no significant changes in antibiotic resistance in the original Keio strains. The presumed functions of these gene products covered a wide range of activities, including metabolism and synthesis, transport, transcription or translation and others. Two competence-gene homologues (ybaV and yhiR) were identified from among these genes. The presumed localizations of these 55 gene products were estimated to be 34 cytoplasmic proteins, 20 in or around the cell surface and 1 unknown location. Our results suggest that these 55 genes may be involved in repressing plasmid uptake during cell-to-cell plasmid transfer.
authors.affiliation: Graduate School of Humanities and Sciences, Nara Women's University, Kitauoya-nishimachi, Nara 630-8506, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Matsuda
authors.forename: Naomi
authors.initials: N
authors.lastname: Kurono
authors.forename: Chinatsu
authors.initials: C
authors.lastname: Kawano
authors.forename: Kozue
authors.initials: K
authors.lastname: Shirota
authors.forename: Akiko
authors.initials: A
authors.lastname: Hirabayashi
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Horino
authors.forename: Rika
authors.initials: R
authors.lastname: Etchuya
authors.forename: Rina
authors.initials: R
authors.lastname: Sobue
authors.forename: Yumi
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Saki
authors.initials: S
authors.lastname: Miyaue
authors.forename: Ayuka
authors.initials: A
authors.lastname: Sekoguchi
authors.forename: Chiaki
authors.initials: C
authors.lastname: Sugiura
authors.forename: Yuka
authors.initials: Y
authors.lastname: Shibata
authors.forename: Miki
authors.initials: M
authors.lastname: Ito
authors.forename: Tsuyako
authors.initials: T
authors.lastname: Ando
authors.forename: Sumio
authors.initials: S
authors.lastname: Maeda
mesh_terms: D003227:Conjugation, Genetic / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D055786:Gene Knockout Techniques; D022761:Gene Transfer, Horizontal / Q000235:genetics*; D009154:Mutation; D010957:Plasmids / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014170:Transformation, Genetic