4UQR

Structure of Bacillus subtilis Nitric Oxide Synthase in complex with N-omega-Nitro-L-Arginine

Summary for 4UQR

• Entry DOI: 10.2210/pdb4uqr/pdb
• Related: 4UQS
• Descriptor: NITRIC OXIDE SYNTHASE OXYGENASE, PROTOPORPHYRIN IX CONTAINING FE, 5,6,7,8-TETRAHYDROBIOPTERIN, ... (8 entities in total)
• Functional Keywords: oxidoreductase, inhibitor
• Biological source: BACILLUS SUBTILIS
• Total number of polymer chains: 1
• Total formula weight: 43596.82

Authors

Holden, J.K.,Poulos, T.L. (deposition date: 2014-06-24, release date: 2014-09-17, Last modification date: 2024-01-10)

Primary citation

Holden, J.K.,Lim, N.,Poulos, T.L.
Identification of Redox Partners and Development of a Novel Chimeric Bacterial Nitric Oxide Synthase for Structure Activity Analyses.
J.Biol.Chem., 289:29437-, 2014

PubMed Abstract: Production of nitric oxide (NO) by nitric oxide synthase (NOS) requires electrons to reduce the heme iron for substrate oxidation. Both FAD and FMN flavin groups mediate the transfer of NADPH derived electrons to NOS. Unlike mammalian NOS that contain both FAD and FMN binding domains within a single polypeptide chain, bacterial NOS is only composed of an oxygenase domain and must rely on separate redox partners for electron transfer and subsequent activity. Here, we report on the native redox partners for Bacillus subtilis NOS (bsNOS) and a novel chimera that promotes bsNOS activity. By identifying and characterizing native redox partners, we were also able to establish a robust enzyme assay for measuring bsNOS activity and inhibition. This assay was used to evaluate a series of established NOS inhibitors. Using the new assay for screening small molecules led to the identification of several potent inhibitors for which bsNOS-inhibitor crystal structures were determined. In addition to characterizing potent bsNOS inhibitors, substrate binding was also analyzed using isothermal titration calorimetry giving the first detailed thermodynamic analysis of substrate binding to NOS.

PubMed: 25194416
DOI: 10.1074/JBC.M114.595165

Experimental method

X-RAY DIFFRACTION (1.72 Å)