Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:5.4.2.8 (phosphomannomutase)
 238 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bacterial canker disease caused by Pseudomonas syringae pv. actinidiae, an emerging pathogen of kiwifruit plants, has recently brought about major economic losses worldwide. Genetic studies on virulence functions of P. syringae pv. actinidiae have not yet been reported and there is little experimental data regarding bacterial genes involved in pathogenesis. In this study, we performed a genetic screen in order to identify transposon mutants altered in the lipolytic activity because it is known that mechanisms of regulation, production, and secretion of enzymes often play crucial roles in virulence of plant pathogens. We aimed to identify the set of secretion and global regulatory loci that control lipolytic activity and also play important roles in in planta fitness. Our screen for altered lipolytic activity phenotype identified a total of 58 Tn5 transposon mutants. Mapping all these Tn5 mutants revealed that the transposons were inserted in genes that play roles in cell division, chemotaxis, metabolism, movement, recombination, regulation, signal transduction, and transport as well as a few unknown functions. Several of these identified P. syringae pv. actinidiae Tn5 mutants, notably the functions affected in phosphomannomutase AlgC, lipid A biosynthesis acyltransferase, glutamate-cysteine ligase, and the type IV pilus protein PilI, were also found affected in in planta survival and/or growth in kiwifruit plants. The results of the genetic screen and identification of novel loci involved in in planta fitness of P. syringae pv. actinidiae are presented and discussed.
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PMID:Identification of Loci of Pseudomonas syringae pv. actinidiae Involved in Lipolytic Activity and Their Role in Colonization of Kiwifruit Leaves. 2811 97

Enzymes sample multiple conformations during their catalytic cycles. Chemical shifts from Nuclear Magnetic Resonance (NMR) are hypersensitive to conformational changes and ensembles in solution. Phosphomannomutase/phosphoglucomutase (PMM/PGM) is a ubiquitous four-domain enzyme that catalyzes phosphoryl transfer across phosphohexose substrates. We compared states the enzyme visits during its catalytic cycle. Collective responses of Pseudomonas PMM/PGM to phosphosugar substrates and inhibitor were assessed using NMR-detected titrations. Affinities were estimated from binding isotherms obtained by principal component analysis (PCA). Relationships among phosphosugar-enzyme associations emerge from PCA comparisons of the titrations. COordiNated Chemical Shifts bEhavior (CONCISE) analysis provides novel discrimination of three ligand-bound states of PMM/PGM harboring a mutation that suppresses activity. Enzyme phosphorylation and phosphosugar binding appear to drive the open dephosphorylated enzyme to the free phosphorylated state, and on toward ligand-closed states. Domain 4 appears central to collective responses to substrate and inhibitor binding. Hydrogen exchange reveals that binding of a substrate analogue enhances folding stability of the domains to a uniform level, establishing a globally unified structure. CONCISE and PCA of NMR spectra have discovered novel states of a well-studied enzyme and appear ready to discriminate other enzyme and ligand binding states.
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PMID:Multiple Ligand-Bound States of a Phosphohexomutase Revealed by Principal Component Analysis of NMR Peak Shifts. 2870 31

Lysobacter enzymogenes, a member of Xanthomonadaceae, is a promising tool to control crop-destroying fungal pathogens. One of its key antifungal virulence factors is the type IV pili that are required for twitching motility. Transposon mutagenesis of L. enzymogenes revealed that the production of type IV pili required the presence of the Le2152 gene, which encodes an AlgC-type phosphomannomutase/phosphoglucomutase (PMM). However, in addition to the cytoplasmic PMM domain, the Le2152 gene product contains a ~200-aa N-terminal periplasmic domain that is anchored in the membrane by two transmembrane segments and belongs to the dCache superfamily of periplasmic sensor domains. Sequence analysis identified similar membrane-anchored PMMs, encoded in conserved coaBC-dut-algC gene clusters, in a variety of gammaproteobacteria, either as the sole PMM gene in the entire genome or in addition to the gene encoding the stand-alone enzymatic domain. Previously overlooked N-terminal periplasmic sensor domains were detected in the well-characterized PMMs of Pseudomonas aeruginosa and Xanthomonas campestris, albeit not in the enzymes from Pseudomonas fluorescens, Pseudomonas putida or Azotobacter vinelandii. It appears that after the initial cloning of the enzymatically active soluble part of P. aeruginosa AlgC in 1991, all subsequent studies utilized N-terminally truncated open reading frames. The N-terminal dCache sensor domain of AlgC is predicted to modulate the PMM activity of the cytoplasmic domain in response to as yet unidentified environmental signal(s). AlgC-like membrane-bound PMMs appear to comprise yet another environmental signalling system that regulates the production of type IV pili and potentially other systems in certain gammaproteobacteria.
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PMID:Two forms of phosphomannomutase in gammaproteobacteria: The overlooked membrane-bound form of AlgC is required for twitching motility of Lysobacter enzymogenes. 3093 49


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