3kzn

Crystal structure of N-acetyl-L-ornithine transcarbamylase complexed with N-acetyl-L-ornirthine

spinqualitylabelsall models 3kzn, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3kzn is a 1 chain structure with sequence from Xanthomonas campestris pv. campestris str. ATCC 33913. This structure supersedes the now removed PDB entry 1zq6. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.8Å Ligands: AOR, GOL, KCX, 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 transcarbamoylase (AOTCase) is a new member of the transcarbamoylase superfamily that is essential for arginine biosynthesis in several eubacteria. We report here crystal structures of the binary complexes of AOTCase with its substrates, carbamoyl phosphate (CP) or N-acetyl-L-ornithine (AORN), and the ternary complex with CP and N-acetyl-L-norvaline. Comparison of these structures demonstrates that the substrate-binding mechanism of this novel transcarbamoylase is different from those of aspartate and ornithine transcarbamoylases, both of which show ordered substrate binding with large domain movements. CP and AORN bind to AOTCase independently, and the main conformational change upon substrate binding is ordering of the 80's loop, with a small domain closure around the active site and little movement of the 240's loop. The structures of the complexes provide insight into the mode of substrate binding and the mechanism of the transcarbamoylation reaction. Structures of N-acetylornithine transcarbamoylase from Xanthomonas campestris complexed with substrates and substrate analogs imply mechanisms for substrate binding and catalysis.,Shi D, Yu X, Roth L, Morizono H, Tuchman M, Allewell NM Proteins. 2006 Aug 1;64(2):532-42. PMID:16741992 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also N-acetylornithine carbamoyltransferase

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