1h70
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Nitric oxide synthase is inhibited by asymmetric NG-methylated derivatives | + | Nitric oxide synthase is inhibited by asymmetric NG-methylated derivatives of arginine whose cellular levels are controlled in part by dimethylarginine dimethylaminohydrolase (DDAH, EC 3.5.3.18). Levels of asymmetric NG,NG-dimethylarginine (ADMA) are known to correlate with certain disease states. Here, the first structure of a DDAH shows an unexpected similarity to arginine:glycine amidinotransferase (EC 2.1.4.1) and arginine deiminase (EC 3.5.3.6), thus defining a superfamily of arginine-modifying enzymes. The identification of a Cys-His-Glu catalytic triad and the structures of a Cys to Ser point mutant bound to both substrate and product suggest a reaction mechanism. Comparison of the ADMA-DDAH and arginine-amidinotransferase complexes reveals a dramatic rotation of the substrate that effectively maintains the orientation of the scissile bond of the substrate with respect to the catalytic residues. The DDAH structure will form a basis for the rational design of selective inhibitors, which are of potential use in modulating NO synthase activity in pathological settings. |
==About this Structure== | ==About this Structure== | ||
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[[Category: nitric oxide synthase inhibitor]] | [[Category: nitric oxide synthase inhibitor]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:58:07 2008'' |
Revision as of 10:58, 21 February 2008
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DDAH FROM PSEUDOMONAS AERUGINOSA. C249S MUTANT COMPLEXED WITH CITRULLINE
Overview
Nitric oxide synthase is inhibited by asymmetric NG-methylated derivatives of arginine whose cellular levels are controlled in part by dimethylarginine dimethylaminohydrolase (DDAH, EC 3.5.3.18). Levels of asymmetric NG,NG-dimethylarginine (ADMA) are known to correlate with certain disease states. Here, the first structure of a DDAH shows an unexpected similarity to arginine:glycine amidinotransferase (EC 2.1.4.1) and arginine deiminase (EC 3.5.3.6), thus defining a superfamily of arginine-modifying enzymes. The identification of a Cys-His-Glu catalytic triad and the structures of a Cys to Ser point mutant bound to both substrate and product suggest a reaction mechanism. Comparison of the ADMA-DDAH and arginine-amidinotransferase complexes reveals a dramatic rotation of the substrate that effectively maintains the orientation of the scissile bond of the substrate with respect to the catalytic residues. The DDAH structure will form a basis for the rational design of selective inhibitors, which are of potential use in modulating NO synthase activity in pathological settings.
About this Structure
1H70 is a Single protein structure of sequence from Pseudomonas aeruginosa with as ligand. Active as Dimethylargininase, with EC number 3.5.3.18 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Structural insights into the hydrolysis of cellular nitric oxide synthase inhibitors by dimethylarginine dimethylaminohydrolase., Murray-Rust J, Leiper J, McAlister M, Phelan J, Tilley S, Santa Maria J, Vallance P, McDonald N, Nat Struct Biol. 2001 Aug;8(8):679-83. PMID:11473257
Page seeded by OCA on Thu Feb 21 12:58:07 2008
