2fg7

N-succinyl-L-ornithine transcarbamylase from B. fragilis complexed with carbamoyl phosphate and N-succinyl-L-norvaline

spinqualitylabelsall models 2fg7, resolution 2.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2fg7 is a 6 chain structure with sequence from Bacteroides fragilis NCTC 9343. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.9Å Ligands: CP, SN0, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q5LI27_BACFN 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 A Bacteroides fragilis gene (argF'(bf)), the disruption of which renders the bacterium auxotrophic for arginine, was expressed and its recombinant protein purified and studied. The novel protein catalyzes the carbamylation of N-succinyl-L-ornithine but not L-ornithine or N-acetyl-L-ornithine, forming N-succinyl-L-citrulline. Crystal structures of this novel transcarbamylase complexed with carbamyl phosphate and N-succinyl-L-norvaline, as well as sulfate and N-succinyl-L-norvaline have been determined and refined to 2.9 and 2.8 A resolution, respectively. They provide structural evidence that this protein is a novel N-succinyl-L-ornithine transcarbamylase. The data provided herein suggest that B. fragilis uses N-succinyl-L-ornithine rather than N-acetyl-L-ornithine for de novo arginine biosynthesis and therefore that this pathway in Bacteroides is different from the canonical arginine biosynthetic pathway of most organisms. Comparison of the structures of the new protein with those recently reported for N-acetyl-L-ornithine transcarbamylase indicates that amino acid residue 90 (B. fragilis numbering) plays an important role in conferring substrate specificity for N-succinyl-L-ornithine versus N-acetyl-L-ornithine. Movement of the 120 loop upon substrate binding occurs in N-succinyl-L-ornithine transcarbamylase, while movement of the 80 loop and significant domain closure take place as in other transcarbamylases. These findings provide new information on the putative role of succinylated intermediates in arginine biosynthesis and on the evolution of transcarbamylases. Structure and catalytic mechanism of a novel N-succinyl-L-ornithine transcarbamylase in arginine biosynthesis of Bacteroides fragilis.,Shi D, Morizono H, Cabrera-Luque J, Yu X, Roth L, Malamy MH, Allewell NM, Tuchman M J Biol Chem. 2006 Jul 21;281(29):20623-31. Epub 2006 May 16. PMID:16704984 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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