3m5c

Crystal structure of N-acetyl-L-ornithine transcarbamylase K302E mutant complexed with PALAO

spinqualitylabelsall models 3m5c, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3m5c is a 1 chain structure with sequence from Xanthomonas campestris pv. campestris. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.85Å Ligands: PA9, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function AOTC_XANCP Catalyzes the conversion of N-acetylornithine to N-acetylcitrulline in an alternative arginine biosynthesis pathway. The enzyme has no activity with ornithine. 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 N-Acetyl-l-ornithine transcarbamylase (AOTCase), rather than ornithine transcarbamylase (OTCase), is the essential carbamylase enzyme in the arginine biosynthesis of several plant and human pathogens. The specificity of this unique enzyme provides a potential target for controlling the spread of these pathogens. Recently, several crystal structures of AOTCase from Xanthomonas campestris (xc) have been determined. In these structures, an unexplained electron density at the tip of the Lys302 side chain was observed. Using (13)C NMR spectroscopy, we show herein that Lys302 is post-translationally carboxylated. The structure of wild-type AOTCase in a complex with the bisubstrate analogue N(delta)-(phosphonoacetyl)-N(alpha)-acetyl-l-ornithine (PALAO) indicates that the carboxyl group on Lys302 forms a strong hydrogen bonding network with surrounding active site residues, Lys252, Ser253, His293, and Glu92 from the adjacent subunit either directly or via a water molecule. Furthermore, the carboxyl group is involved in binding N-acetyl-l-ornithine via a water molecule. Activity assays with the wild-type enzyme and several mutants demonstrate that the post-translational modification of lysine 302 has an important role in catalysis. Reversible post-translational carboxylation modulates the enzymatic activity of N-acetyl-L-ornithine transcarbamylase.,Li Y, Yu X, Ho J, Fushman D, Allewell NM, Tuchman M, Shi D Biochemistry. 2010 Aug 17;49(32):6887-95. PMID:20695527 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also N-acetylornithine carbamoyltransferase

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