2NSI

HUMAN INDUCIBLE NITRIC OXIDE SYNTHASE, ZN-FREE, SEITU COMPLEX

Summary for 2NSI

• Entry DOI: 10.2210/pdb2nsi/pdb
• Related: 1NSI
• Descriptor: PROTEIN (NITRIC OXIDE SYNTHASE), SULFATE ION, PROTOPORPHYRIN IX CONTAINING FE, ... (5 entities in total)
• Functional Keywords: nitric oxide synthase, heme protein, tetrahydrobiopterin, oxidoreductase
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 4
• Total formula weight: 203534.32

Authors

Li, H.,Raman, C.S.,Glaser, C.B.,Blasko, E.,Young, T.A.,Parkinson, J.F.,Whitlow, M.,Poulos, T.L. (deposition date: 1999-01-11, release date: 2000-01-07, Last modification date: 2024-10-30)

Primary citation

Li, H.,Raman, C.S.,Glaser, C.B.,Blasko, E.,Young, T.A.,Parkinson, J.F.,Whitlow, M.,Poulos, T.L.
Crystal structures of zinc-free and -bound heme domain of human inducible nitric-oxide synthase. Implications for dimer stability and comparison with endothelial nitric-oxide synthase.
J.Biol.Chem., 274:21276-21284, 1999

PubMed Abstract: The crystal structures of the heme domain of human inducible nitric-oxide synthase (NOS-2) in zinc-free and -bound states have been solved. In the zinc-free structure, two symmetry-related cysteine residues form a disulfide bond. In the zinc-bound state, these same two cysteine residues form part of a zinc-tetrathiolate (ZnS(4)) center indistinguishable from that observed in the endothelial isoform (NOS-3). As in NOS-3, ZnS(4) plays a key role in stabilizing intersubunit contacts and in maintaining the integrity of the cofactor (tetrahydrobiopterin) binding site of NOS-2. A comparison of NOS-2 and NOS-3 structures illustrates the conservation of quaternary structure, tertiary topology, and substrate and cofactor binding sites, in addition to providing insights on isoform-specific inhibitor design. The structural comparison also reveals that pterin binding does not preferentially stabilize the dimer interface of NOS-2 over NOS-3.

PubMed: 10409685
DOI: 10.1074/jbc.274.30.21276

Experimental method

X-RAY DIFFRACTION (3 Å)