1ynh

Crystal Structure of N-Succinylarginine Dihydrolase, AstB, bound to Substrate and Product, an Enzyme from the Arginine Catabolic Pathway of Escherichia coli

spinqualitylabelsall models 1ynh, resolution 1.95Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1ynh is a 4 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.95Å Ligands: K, SUO Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ASTB_ECOLI Catalyzes the hydrolysis of N(2)-succinylarginine into N(2)-succinylornithine, ammonia and CO(2). 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 ammonia-producing arginine succinyltransferase pathway is the major pathway in Escherichia coli and related bacteria for arginine catabolism as a sole nitrogen source. This pathway consists of five steps, each catalyzed by a distinct enzyme. Here we report the crystal structure of N-succinylarginine dihydrolase AstB, the second enzyme of the arginine succinyltransferase pathway, providing the first structural insight into enzymes from this pathway. The enzyme exhibits a pseudo 5-fold symmetric alpha/beta propeller fold of circularly arranged betabetaalphabeta modules enclosing the active site. The crystal structure indicates clearly that this enzyme belongs to the amidinotransferase (AT) superfamily and that the active site contains a Cys-His-Glu triad characteristic of the AT superfamily. Structures of the complexes of AstB with the reaction product and a C365S mutant with bound the N-succinylarginine substrate suggest a catalytic mechanism that consists of two cycles of hydrolysis and ammonia release, with each cycle utilizing a mechanism similar to that proposed for arginine deiminases. Like other members of the AT superfamily of enzymes, AstB possesses a flexible loop that is disordered in the absence of substrate and assumes an ordered conformation upon substrate binding, shielding the ligand from the bulk solvent, thereby controlling substrate access and product release. Crystal structure of N-succinylarginine dihydrolase AstB, bound to substrate and product, an enzyme from the arginine catabolic pathway of Escherichia coli.,Tocilj A, Schrag JD, Li Y, Schneider BL, Reitzer L, Matte A, Cygler M J Biol Chem. 2005 Apr 22;280(16):15800-8. Epub 2005 Feb 9. PMID:15703173 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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