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Ternary structure of neuronal nitric oxide synthase with NHA and CO boundTernary structure of neuronal nitric oxide synthase with NHA and CO bound
Structural highlights
FunctionNOS1_RAT Produces nitric oxide (NO) which is a messenger molecule with diverse functions throughout the body. In the brain and peripheral nervous system, NO displays many properties of a neurotransmitter. Inhibitory transmitter for non-adrenergic and non-cholinergic nerves in the colorectum. Probably has nitrosylase activity and mediates cysteine S-nitrosylation of cytoplasmic target proteins such SRR. Inhibitory transmitter for non-adrenergic and non-cholinergic nerves in the colorectum. Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe X-ray structures of neuronal nitric oxide synthase (nNOS) with N(omega)-hydroxy-l-arginine (l-NHA) and CO (or NO) bound have been determined at 1.91-2.2 A resolution. Microspectrophotometric techniques confirmed reduced redox state and the status of diatomic ligand complexes during X-ray diffraction data collection. The structure of nNOS-NHA-NO, a close mimic to the dioxygen complex, provides a picture of the potential interactions between the heme-bound diatomic ligand, substrate l-NHA, and the surrounding protein and solvent structure environment. The OH group of l-NHA in the X-ray structures deviates from the plane of the guanidinium moiety substantially, indicating that the OH-bearing, protonated guanidine N(omega) nitrogen of l-NHA has substantial sp(3) hybridization character. This nitrogen geometry, different from that of the guanidinium N(omega) nitrogen of l-arginine, allows a hydrogen bond to be donated to the proximal oxygen of the heme-bound dioxygen complex, thus preventing cleavage of the O-O bond. Instead, it favors the stabilization of the ferric-hydroperoxy intermediate, Fe(3+)-OOH(-), which serves as the active oxidant in the conversion of l-NHA to NO and citrulline in the second reaction of the NOS. Single Crystal Structural and Absorption Spectral Characterizations of Nitric Oxide Synthase Complexed with N(omega)-Hydroxy-l-arginine and Diatomic Ligands (,).,Doukov T, Li H, Soltis M, Poulos TL Biochemistry. 2009 Oct 9. PMID:19791770[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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