Cloning and Characterization of the Flavobacterium johnsoniae Gliding Motility Genes gldD and gldE

Abstract

Cells of Flavobacterium johnsoniae move over surfaces by a process known as gliding motility. The mechanism of this form of motility is not known. Cells of F. johnsoniae propel latex spheres along their surfaces, which is thought to be a manifestation of the motility machinery. Three of the genes that are required for F. johnsoniae gliding motility, gldA, gldB, and ftsX, have recently been described. Tn4351 mutagenesis was used to identify another gene, gldD, that is needed for gliding. Tn4351-induced gldD mutants formed nonspreading colonies, and cells failed to glide. They also lacked the ability to propel latex spheres and were resistant to bacteriophages that infect wild-type cells. Introduction of wild-type gldD into the mutants restored motility, ability to propel latex spheres, and sensitivity to bacteriophage infection. gldD codes for a cytoplasmic membrane protein that does not exhibit strong sequence similarity to proteins of known function. gldE, which lies immediately upstream of gldD, encodes another cytoplasmic membrane protein that may be involved in gliding motility. Overexpression of gldE partially suppressed the motility defects of a gldB point mutant, suggesting that GldB and GldE may interact. GldE exhibits sequence similarity to Borrelia burgdorferi TlyC and Salmonella enterica serovar Typhimurium CorC.

Flavobacterium johnsoniae GldH Is a Lipoprotein That Is Required for Gliding Motility and Chitin Utilization

“…F. johnsoniae UW101 (ATCC 17061) was the wild-type strain used in these studies, and all mutants were derived from this strain. gld mutants used in this study which were previously characterized included the gldA mutant CJ101-288 (1), the gldB mutant CJ569 (Tn4351 insert ⍀569) (15), the gldD mutant CJ282 (14), the gldF mutant CJ787 (13), and the gldG mutant CJ776 (13). Fifty nonmotile mutants of F. johnsoniae were obtained from J.…”

“…Microscopic observations of cell movement. Wild-type and mutant cells of F. johnsoniae were examined for movement over glass and agar surfaces and for their ability to propel polystyrene latex spheres by phase-contrast microscopy as previously described (14,15), except that cells grown to late exponential phase in CYE broth were examined both directly in their growth medium and after harvesting by centrifugation and suspension in 10 mM Tris (pH 7.5), since it was determined that this treatment often resulted in increased binding of latex spheres, increased sphere movement, and increased gliding motility on glass surfaces.…”

“…Genetic techniques have been developed for F. johnsoniae, and several genes that are required for gliding have been identified (1,(13)(14)(15)23). gldA, gldF, and gldG are thought to encode components of an ATP-binding cassette (ABC) transporter that is required for motility.…”

Flavobacterium johnsoniaeGliding Motility Genes Identified bymarinerMutagenesis

“…gldA, gldF, and gldG are thought to encode components of an ATPbinding cassette (ABC) transporter that is required for motility (1,15). Genes encoding lipoproteins that are required for gliding (GldB, GldD, GldH, GldI, and GldJ) have also been identified (5,16,17,27,28). Cells with mutations in any of these genes are completely nonmotile.…”

Mutations in Flavobacterium johnsoniae secDF Result in Defects in Gliding Motility and Chitin Utilization

“…F. johnsoniae was mutagenized with Tn4351, and 154 mutants that formed nonspreading colonies were isolated as described previously (13). Thirty-six of the mutants were completely nonmotile and had Tn4351 insertions in gld genes that were previously described (1,(11)(12)(13)18). Another 14 mutants had defects in cell division in addition to loss of motility, similar to those of ftsX mutants (15).…”