4nse

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spinqualitylabelsall models 4nse, resolution 1.95Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

BOVINE ENDOTHELIAL NITRIC OXIDE SYNTHASE, H4B-FREE, L-ARG COMPLEX

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

4NSE is a Single protein structure of sequence from Bos taurus with ACT, CAC, ZN, ARG, HEM and GOL as ligands. Active as Nitric-oxide synthase, with EC number 1.14.13.39 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

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