Life Sciences Commons^™

Gel Shift Analysis Of The Empa Promoter Region In Vibrio Anguillarum, Steven Denkin, Pedja Sekaric, David Nelson

David R. Nelson

BACKGROUND: The induction of metalloprotease encoded by empA in Vibrio anguillarum occurs at high cell density in salmon intestinal mucus. Previously we have shown that there are significant differences in empA expression in two strains of V. anguillarum, M93Sm and NB10. It is hypothesized that differences in empA regulation are due to differences in binding of regulatory elements.

RESULTS: Two strains of V. anguillarum, M93Sm and NB10, were examined and compared for the presence of DNA regulatory proteins that bind to and control the empA promoter region. Gel mobility shift assays, using a digoxigenin (DIG)-labeled oligomer containing a lux box-like …

Cj1121c, A Novel Udp-4-Keto-6-Deoxy-Glcnac C-4 Aminotransferase Essential For Protein Glycosylation And Virulence In Campylobacter Jejuni, Somalinga Vijayakumar, Alexandra Merkx-Jacques, Dinath Ratnayake, Irene Gryski, Ravinder Obhi, Sébastien Houle, Charles M Dozois, Carole Creuzenet

Alexandra Merkx-Jacques

Campylobacter jejuni produces glycoproteins that are essential for virulence. These glycoproteins carry diacetamidobacillosamine (DAB), a sugar that is not found in humans. Hence, the enzymes responsible for DAB synthesis represent potential therapeutic targets. We describe the biochemical characterization of Cj1121c, a putative aminotransferase encoded by the general protein glycosylation locus, to assess its role in DAB biosynthesis. By using overexpressed and affinity-purified enzyme, we demonstrate that Cj1121c has pyridoxal phosphate- and glutamate-dependent UDP-4-keto-6-deoxy-GlcNAc C-4 transaminase activity and produces UDP-4-amino-4,6-dideoxy-GlcNAc. This is consistent with a role in DAB biosynthesis and distinguishes Cj1121c from Cj1294, a homologous UDP-2-acetamido-2,6-dideoxy-beta-l-arabino-4-hexulose C-4 aminotransferase that we …

The Helicobacter Pylori Flaa1 And Wbpb Genes Control Lipopolysaccharide And Flagellum Synthesis And Function, Alexandra Merkx-Jacques, R. Obhi, G. Bethune, C. Creuzenet

Alexandra Merkx-Jacques

flaA1 and wbpB are conserved genes with unknown biological function in Helicobacter pylori. Since both genes are predicted to be involved in lipopolysaccharide (LPS) biosynthesis, flagellum assembly, or protein glycosylation, they could play an important role in the pathogenesis of H. pylori. To determine their biological role, both genes were disrupted in strain NCTC 11637. Both mutants exhibited altered LPS, with loss of most O-antigen and core modification, and increased sensitivity to sodium dodecyl sulfate compared to wild-type bacteria. These defects could be complemented in a gene-specific manner. Also, flaA1 could complement these defects in the wbpB mutant, suggesting a …