2nse: Difference between revisions

[[Image:2nse.jpg|left|200px]]<br /><applet load="2nse" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

2NSE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=CAC:'>CAC</scene>, <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=ARG:'>ARG</scene>, <scene name='pdbligand=HEM:'>HEM</scene>, <scene name='pdbligand=H4B:'>H4B</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Nitric-oxide_synthase Nitric-oxide synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.13.39 1.14.13.39] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2NSE OCA].  

[[Category: Masters, B S.S.]]

[[Category: Poulos, T L.]]

[[Category: Raman, C S.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:10:29 2008''