Functional Analysis of Genes in the rfb Locus of Leptospira borgpetersenii Serovar Hardjo Subtype Hardjobovis
AUTOR(ES)
Bulach, Dieter M.
FONTE
American Society for Microbiology
RESUMO
Lipopolysaccharide (LPS) is a key antigen in immunity to leptospirosis. Its biosynthesis requires enzymes for the biosynthesis and polymerization of nucleotide sugars and the transport through and attachment to the bacterial membrane. The genes encoding these functions are commonly clustered into loci; for Leptospira borgpetersenii serovar Hardjo subtype Hardjobovis, this locus, named rfb, spans 36.7 kb and contains 31 open reading frames, of which 28 have been assigned putative functions on the basis of sequence similarity. Characterization of the function of these genes is hindered by the fact that it is not possible to construct isogenic mutant strains in Leptospira. We used two approaches to circumvent this problem. The first was to clone the entire locus into a heterologous host system and determine if a “recombinant” LPS or polysaccharide was synthesized in the new host. The second approach used putative functions to identify mutants in other bacterial species whose mutations might be complemented by genes on the leptospiral rfb locus. This approach was used to investigate the function of three genes in the leptospiral rfb locus and demonstrated function for orfH10, which complemented a wbpM strain of Pseudomonas aeruginosa, and orfH13, which complemented an rfbW strain of Vibrio cholerae. However, despite the similarity of OrfH11 to WecC, a wecC strain of E. coli was not complemented by orfH11. The predicted protein encoded by orfH8 is similar to GalE from a number of organisms. A Salmonella enterica serovar Typhimurium strain producing no GalE was used as a background in which orfH8 produced detectable GalE enzyme activity.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=101650Documentos Relacionados
- Restriction fragment length polymorphisms distinguish Leptospira borgpetersenii serovar hardjo type hardjo-bovis isolates from different geographical locations.
- DNA probe for detection of the Leptospira interrogans serovar hardjo genotype hardjo-bovis.
- Sample preparation method for polymerase chain reaction-based semiquantitative detection of Leptospira interrogans serovar hardjo subtype hardjobovis in bovine urine.
- Repetitive sequence element cloned from Leptospira interrogans serovar hardjo type hardjo-bovis provides a sensitive diagnostic probe for bovine leptospirosis.
- Identification and characterization of the dTDP-rhamnose biosynthesis and transfer genes of the lipopolysaccharide-related rfb locus in Leptospira interrogans serovar Copenhageni.