Journal: PLoS Pathogens
Article Title: Discovery and characterization of a Gram-positive Pel polysaccharide biosynthetic gene clusterA systematic pipeline for classifying bacterial operons reveals the evolutionary landscape of biofilm machineries
Figure Lengend Snippet: Model for B . cereus ATCC 10987 Pel biosynthesis. PelF is a glycosyltransferase that polymerizes UDP-GalNAc to generate the Pel polysaccharide (light pink triangles are acetyl groups, red hexagons are GalN monosaccharide units, dark red teardrops are UDP). Once synthesized, Pel is exported across the cytoplasmic membrane via PelD, PelE, PelA DA , and/or PelG. PelA DA , corresponding to the deacetylase domain of P . aeruginosa PelA, partially deacetylates the polymer to generate mature Pel. PelA H , corresponding to the hydrolase domain of P . aeruginosa PelA, performs a role in regulating overall biofilm formation levels of ATCC 10987. Pel biosynthesis requires binding of the nucleotide second messenger c-di-GMP to the I-site of the cytoplasmic GGDEF domain of PelD. CdgF is a diguanylate cyclase that synthesizes c-di-GMP from two GTP molecules and thus positively regulates Pel biosynthesis. CdgE is a phosphodiesterase that converts c-di-GMP to 5’-pGpG and thus negatively regulates Pel biosynthesis. GalE epimerizes UDP-GlcNAc to UDP-GalNAc, which is presumably utilized by PelF for Pel polymerization. C, cytoplasm; CM, cytoplasmic membrane; EC, extracellular space; PG, peptidoglycan; UDP, uridine di-phosphate; GlcNAc, N- acetylglucosamine; GalNAc, N -acetylgalactosamine; GTP, guanosine tri-phosphate; c-di-GMP, cyclic-3’,5’-dimeric guanosine monophosphate; 5’-pGpG, phosphoguanylyl-3',5'-guanosine.
Article Snippet: To assess whether cdgF and cdgE play a role in biofilm formation by ATCC 10987, we generated cdgF and cdgE deletion mutant strains and analyzed biofilm formation using the crystal violet assay ( ).
Techniques: Synthesized, Histone Deacetylase Assay, Binding Assay