1nse
From Proteopedia
BOVINE ENDOTHELIAL NITRIC OXIDE SYNTHASE
Overview
Nitric oxide, a key signaling molecule, is produced by a family of enzymes collectively called nitric oxide synthases (NOS). Here, we report the crystal structure of the heme domain of endothelial NOS in tetrahydrobiopterin (H4B)-free and -bound forms at 1.95 A and 1.9 A resolution, respectively. In both structures a zinc ion is tetrahedrally coordinated to pairs of symmetry-related cysteine residues at the dimer interface. The phylogenetically conserved Cys-(X)4-Cys motif and its strategic location establish a structural role for the metal center in maintaining the integrity of the H4B-binding site. The unexpected recognition of the substrate, L-arginine, at the H4B site indicates that this site is poised to stabilize a positively charged pterin ring and suggests a model involving a cationic pterin radical in the catalytic cycle.
About this Structure
1NSE is a Single protein structure of sequence from Bos taurus. Full crystallographic information is available from OCA.
Reference
Crystal structure of constitutive endothelial nitric oxide synthase: a paradigm for pterin function involving a novel metal center., Raman CS, Li H, Martasek P, Kral V, Masters BS, Poulos TL, Cell. 1998 Dec 23;95(7):939-50. PMID:9875848 Page seeded by OCA on Sat May 3 02:55:18 2008
