3uj7

Phosphoethanolamine methyltransferase from Plasmodium falciparum in complex with SAM and PO4

spinqualitylabelsall models 3uj7, resolution 1.55Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3uj7 is a 2 chain structure with sequence from Plafa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: PO4, SAM Related: 3uj6, 3uj8, 3uj9, 3uja, 3ujb, 3ujc, 3ujd Gene: PMT (PLAFA) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed In the malarial parasite Plasmodium falciparum, a multi-functional phosphoethanolamine methyltransferase (PfPMT) catalyzes the methylation of phosphoethanolamine (pEA) to phosphocholine (pCho) for membrane biogenesis. This pathway is also found in plant and nematodes, but PMT from these organisms use multiple methyltransferse domains for the AdoMet reactions. Because PfPMT is essential for normal growth and survival of Plasmodium and is not found in humans, it is an anti-parasitic target. Here we describe the 1.55 A resolution crystal structure of PfPMT in complex with S-adenosylmethionine (AdoMet) by single-wavelength anomalous dispersion phasing. In addition, 1.19-1.52 A resolution structures of PfPMT with pEA (substrate), pCho (product), sinefungin (inhibitor), and both pEA and S-adenosylhomocysteine (AdoCys) bound were determined. These structures suggest that domain rearrangements occur upon ligand binding and provide insight on active site architecture defining the AdoMet and phosphobase binding sites. Functional characterization of 27 site-directed mutants identifies critical active site residues and suggests that Tyr19 and His132 form a catalytic dyad. Kinetic analysis, isothermal titration calorimetry, and protein crystallography of the Y19F and H132A mutants suggest a reaction mechanism for the PMT. Not only are Tyr19 and His132 required for phosphobase methylation, but they also form a 'catalytic' latch that locks ligands in the active site and orders the site for catalysis. This study provides the first insight on this anti-parasitic target enzyme essential for survival of the malaria parasite; however, further studies of the multi-domain PMT from plants and nematodes are needed to understand the evolutionary division of metabolic function in the phosphobase pathway of these organisms. Structure and Reaction Mechanism of Phosphoethanolamine Methyltransferase from the Malaria Parasite Plasmodium falciparum: An Anti-Parasitic Drug Target.,Lee SG, Kim Y, Alpert TD, Nagata A, Jez JM J Biol Chem. 2011 Nov 23. PMID:22117061 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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