title: Formation and dimerization of the phosphodiesterase active site of the Pseudomonas aeruginosa MorA, a bi-functional c-di-GMP regulator.
abstract: Diguanylate cyclases (DGC) and phosphodiesterases (PDE), respectively synthesise and hydrolyse the secondary messenger cyclic dimeric GMP (c-di-GMP), and both activities are often found in a single protein. Intracellular c-di-GMP levels in turn regulate bacterial motility, virulence and biofilm formation. We report the first structure of a tandem DGC-PDE fragment, in which the catalytic domains are shown to be active. Two phosphodiesterase states are distinguished by active site formation. The structures, in the presence or absence of c-di-GMP, suggest that dimerisation and binding pocket formation are linked, with dimerisation being required for catalytic activity. An understanding of PDE activation is important, as biofilm dispersal via c-di-GMP hydrolysis has therapeutic effects on chronic infections.
authors.affiliation: Centre for Biological Sciences and Institute for Life Sciences, Life Sciences Building B85, The University of Southampton, University Rd, Southampton, Hampshire, SO17 1BJ, United Kingdom.
authors.forename: Curtis William
authors.initials: CW
authors.lastname: Phippen
authors.affiliation: Centre for Biological Sciences and Institute for Life Sciences, Life Sciences Building B85, The University of Southampton, University Rd, Southampton, Hampshire, SO17 1BJ, United Kingdom.
authors.forename: Halina
authors.initials: H
authors.lastname: Mikolajek
authors.affiliation: Centre for Biological Sciences and Institute for Life Sciences, Life Sciences Building B85, The University of Southampton, University Rd, Southampton, Hampshire, SO17 1BJ, United Kingdom.
authors.forename: Henry George
authors.initials: HG
authors.lastname: Schlaefli
authors.affiliation: Centre for Biological Sciences and Institute for Life Sciences, Life Sciences Building B85, The University of Southampton, University Rd, Southampton, Hampshire, SO17 1BJ, United Kingdom.
authors.forename: Charles William
authors.initials: CW
authors.lastname: Keevil
authors.affiliation: Centre for Biological Sciences and Institute for Life Sciences, Life Sciences Building B85, The University of Southampton, University Rd, Southampton, Hampshire, SO17 1BJ, United Kingdom.
authors.forename: Jeremy Stephen
authors.initials: JS
authors.lastname: Webb
authors.affiliation: Centre for Biological Sciences and Institute for Life Sciences, Life Sciences Building B85, The University of Southampton, University Rd, Southampton, Hampshire, SO17 1BJ, United Kingdom. Electronic address: Ivo.Tews@soton.ac.uk.
authors.forename: Ivo
authors.initials: I
authors.lastname: Tews
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000737:chemistry* / Q000378:metabolism*; D000595:Amino Acid Sequence; D055162:Biocatalysis; D020134:Catalytic Domain; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D029968:Escherichia coli Proteins / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019761:Phosphorus-Oxygen Lyases / Q000378:metabolism; D055503:Protein Multimerization / Q000187:drug effects; D020836:Protein Structure, Quaternary; D011550:Pseudomonas aeruginosa / Q000201:enzymology*
chemical_list: D029968:Escherichia coli Proteins; C062025:bis(3',5')-cyclic diguanylic acid; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D019761:Phosphorus-Oxygen Lyases; C060720:diguanylate cyclase; D006152:Cyclic GMP
keywords: Biofilm dispersal; Cyclic dimeric guanosine monophosphate; Diguanylate cyclases; Motility regulator A; Phosphodiesterases