2j89 | pdb_00002j89

Functional and structural aspects of poplar cytosolic and plastidial type A methionine sulfoxide reductases

spinqualitylabelsall models 2j89, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2j89 is a 1 chain structure with sequence from Poptr. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: BME NonStd Res: CSO Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The genome of Populus trichocarpa contains five methionine sulfoxide reductase A genes. Here, both cytosolic (cMsrA) and plastidial (pMsrA) poplar MsrAs were analyzed. The two recombinant enzymes are active in the reduction of methionine sulfoxide with either dithiothreitol or poplar thioredoxin as a reductant. In both enzymes, five cysteines, at positions 46, 81, 100, 196, and 202, are conserved. Biochemical and enzymatic analyses of the cysteine-mutated MsrAs support a catalytic mechanism involving three cysteines at positions 46, 196, and 202. Cys(46) is the catalytic cysteine, and the two C-terminal cysteines, Cys(196) and Cys(202), are implicated in the thioredoxin-dependent recycling mechanism. Inspection of the pMsrA x-ray three-dimensional structure, which has been determined in this study, strongly suggests that contrary to bacterial and Bos taurus MsrAs, which also contain three essential Cys, the last C-terminal Cys(202), but not Cys(196), is the first recycling cysteine that forms a disulfide bond with the catalytic Cys(46). Then Cys(202) forms a disulfide bond with the second recycling cysteine Cys(196) that is preferentially reduced by thioredoxin. In agreement with this assumption, Cys(202) is located closer to Cys(46) compared with Cys(196) and is included in a (202)CYG(204) signature specific for most plant MsrAs. The tyrosine residue corresponds to the one described to be involved in substrate binding in bacterial and B. taurus MsrAs. In these MsrAs, the tyrosine residue belongs to a similar signature as found in plant MsrAs but with the first C-terminal cysteine instead of the last C-terminal cysteine. Functional and structural aspects of poplar cytosolic and plastidial type a methionine sulfoxide reductases.,Rouhier N, Kauffmann B, Tete-Favier F, Palladino P, Gans P, Branlant G, Jacquot JP, Boschi-Muller S J Biol Chem. 2007 Feb 2;282(5):3367-78. Epub 2006 Nov 29. PMID:17135266 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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