Submitted to: Acta Crystallographica Section B: Structural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/26/2006
Publication Date: 9/20/2006
Citation: Gohain, N., Thomashow, L.S., Mavrodi, D.V., Blankenfeldt, W. 2006. The purification, crystallization and preliminary structural characterization of PhzM, a phenazine-modifying methyltransferase from Pseudomonas aeruginosa. Acta Crystallographica B., 2006. F62, 989-992 Part 10. Interpretive Summary: The blue chloroform-soluble bacterial metabolite pyocyanin contributes to the survival and virulence of Pseudomonas aeruginosa, an important pathogen of burn victims and immunocompromised people. Little is known about two enzymes, designated PhzM and PhzS, that function in the synthesis of pyocyanin. In this study, the PhzM enzyme was purified and crystallized. Native crystals contained two copies of the enzyme in each enzymatic unit. The study provides valuable new information about how this enzyme functions to introduce a methyl group onto a nitrogen molecule in the ring portion of the pyocyanin molecule.
Technical Abstract: Pyocyanin, phenazine-1-carboxylic acid and more than 70 related compounds collectively known as phenazines are produced by various species of Pseudomonas, including the fluorescent pseudomonad P. aeruginosa, a Gramnegative opportunistic pathogen in humans and animals. P. aeruginosa synthesizes a characteristic blue water-soluble compound called pyocyanin (1-hydroxy-5-methyl-phenazine). Two enzymes designated PhzM and PhzS are involved in the terminal steps of its synthesis and very little is known about these enzymes. In this study, PhzM, a dimeric S-adenosylmethionine-dependent methyltransferase, was purified and crystallized from PEG 3350/sodium cacodylate/sodium citrate pH 6.5. The crystals belong to space group P1, with unit-cell parameters a = 46.1, b = 61.8, c = 69.6 A ° , _ = 96.3, _ = 106.6, _ = 106.9_. They contain one dimer in the asymmetric unit and diffract to a resolution of 1.8 A ° . Anomalous data to 2.3 A ° resolution have been collected from selenol- methionine-labelled PhzM.