Genome-wide screening of genes required for swarming motility in Escherichia coli K-12.
Escherichia coli K-12 has the ability to migrate on semisolid media by means of swarming motility. A systematic and comprehensive collection of gene-disrupted E. coli K-12 mutants (the Keio collection) was used to identify the genes involved in the swarming motility of this bacterium. Of the 3,985 nonessential gene mutants, 294 were found to exhibit a strongly repressed-swarming phenotype. Further, 216 of the 294 mutants displayed no significant defects in swimming motility; therefore, the 216 genes were considered to be specifically associated with the swarming phenotype. The swarming-associated genes were classified into various functional categories, indicating that swarming is a specialized form of motility that requires a wide variety of cellular activities. These genes include genes for tricarboxylic acid cycle and glucose metabolism, iron acquisition, chaperones and protein-folding catalysts, signal transduction, and biosynthesis of cell surface components, such as lipopolysaccharide, the enterobacterial common antigen, and type 1 fimbriae. Lipopolysaccharide and the enterobacterial common antigen may be important surface-acting components that contribute to the reduction of surface tension, thereby facilitating the swarm migration in the E. coli K-12 strain.
Inoue
Tetsuyoshi
T
Department of Oral Microbiology, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 2-5-1, Shikata, Okayama 700-8525, Japan. inouet@cc.okayama-u.ac.jp
Shingaki
Ryuji
R
Hirose
Shotaro
S
Waki
Kaori
K
Mori
Hirotada
H
Fukui
Kazuhiro
K
D000942:Antigens, Bacterial / Q000235:genetics / Q000502:physiology; D002952:Citric Acid Cycle / Q000235:genetics / Q000502:physiology; D004926:Escherichia coli / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D010861:Fimbriae, Bacterial / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D017353:Gene Deletion; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D005947:Glucose / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D018832:Molecular Chaperones / Q000235:genetics / Q000502:physiology; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D017510:Protein Folding; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology
D000942:Antigens, Bacterial; D029968:Escherichia coli Proteins; D018832:Molecular Chaperones; D011135:Polysaccharides, Bacterial; D005947:Glucose