Fimbrial biogenesis genes of Pseudomonas aeruginosa: pilW and pilX increase the similarity of type 4 fimbriae to the GSP protein-secretion systems and pilY1 encodes a gonococcal PilC homologue.
Type 4 fimbriae of Pseudomonas aeruginosa are surface filaments involved in host colonization. They mediate both attachment to host epithelial cells and flagelia-independent twitching motility. Four additional genes, pilW, pilX, pilY1 and pilY2, are located on Spel fragment E in the 5 kb intergenic region between the previously characterized genes pilV and pilE, which encode prepilin-like proteins involved in type 4 fimbrial biogenesis. The phenotypes of a transposon insertion and other mutations constructed by allelic exchange show that these genes are involved in the assembly of type 4 fimbriae. The PilW and PilX proteins are membrane located, possess the hydrophobic N-terminus characteristic of prepilin-like proteins, and appear to belong to the GspJ and GspK group of proteins that are required for protein secretion in a wide range of Gram-negative bacteria. These findings increase the similarities between the fimbrial biogenesis and the Gsp-based protein-secretion supersystems. PilY1 is a large protein with C-terminal homology to the PilC2 protein of Neisseria gonorrhoeae, thought to be a fimbrial tip-associated adhesin, and which, like PilY1, is involved in fimbrial assembly. PilY1 appears to be located in both the membrane and the external fimbrial fractions. PilY2 is a small protein that appears to play a subtle role in fimbrial biogenesis and represents a new class of protein.
Centre for Molecular and Cellular Biology, University of Queensland, Brisbane, Australia.
R A
RA
Alm
J P
JP
Hallinan
A A
AA
Watson
J S
JS
Mattick
D000483:Alleles; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial / Q000235:genetics*; D015870:Gene Expression; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D009344:Neisseria gonorrhoeae / Q000235:genetics; D016366:Open Reading Frames; D010641:Phenotype; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008565:Membrane Proteins; C103854:PilX protein, Pseudomonas aeruginosa; C103855:PilY1 protein, Pseudomonas aeruginosa; C079208:pilC protein, Neisseria gonorrhoeae; D036781:Fimbriae Proteins