Function and Biology

Structure of bovine endothelial nitric oxide synthase heme domain in complex with 3,5-bis(2-(6-amino-4-methylpyridin-2-yl)ethyl)benzonitrile

Source organism: Bos taurus
Biochemical function: nitric-oxide synthase activity
Biological process: nitric oxide biosynthetic process
Cellular component: not assigned

EC 1.14.13.39: Nitric-oxide synthase (NADPH)

Reaction catalysed:
2 L-arginine + 3 NADPH + 4 O(2) = 2 L-citrulline + 2 nitric oxide + 3 NADP(+) + 4 H(2)O.
Comments:
  • The enzyme consists of linked oxygenase and reductase domains.
  • The eukaryotic enzyme binds FAD, FMN, heme (iron protoporphyrin IX) and tetrahydrobiopterin, and its two domains are linked via a regulatory calmodulin-binding domain.
  • Upon calcium-induced calmodulin binding, the reductase and oxygenase domains form a complex, allowing electrons to flow from NADPH via FAD and FMN to the active center.
  • The reductase domain of the enzyme from the bacterium Sorangium cellulosum utilizes a [2Fe-2S] cluster to transfer the electrons from NADPH to the active center.
  • Cf. EC 1.14.14.47.
Systematic name:
L-arginine,NADPH:oxygen oxidoreductase (nitric-oxide-forming)
Alternative Name(s):
  • NADPH-diaphorase
  • NO synthase
  • Endothelium-derived relaxation factor-forming enzyme
  • Endothelium-derived relaxing factor synthase
  • Nitric oxide synthetase
  • Nitric-oxide synthetase
  • NOS (gene name)

GO terms

Biochemical function:
Biological process:
Cellular component:
  • not assigned

Sequence family

InterPro InterPro annotations
IPR004030
Domain description: Nitric oxide synthase, N-terminal
Occurring in:
  1. Nitric oxide synthase, endothelial
IPR036119
Domain description: Nitric oxide synthase, N-terminal domain superfamily
Occurring in:
  1. Nitric oxide synthase, endothelial

Structure domains

CATH CATH domains
3.90.340.10
Class: Alpha Beta
Architecture: Alpha-Beta Complex
Topology: Nitric Oxide Synthase; Chain A, domain 1
Homology: Nitric Oxide Synthase; Chain A, domain 1
Occurring in:
  1. Nitric oxide synthase, endothelial
1 copy of CATH domain 3.90.340.10 (Nitric Oxide Synthase; Chain A, domain 1) in Nitric oxide synthase, endothelial in PDB 4imx.
3.90.440.10
Class: Alpha Beta
Architecture: Alpha-Beta Complex
Topology: Nitric Oxide Synthase;Heme Domain; Chain A, domain 2
Homology: Nitric Oxide Synthase;Heme Domain;Chain A domain 2
Occurring in:
  1. Nitric oxide synthase, endothelial
1 copy of CATH domain 3.90.440.10 (Nitric Oxide Synthase;Heme Domain; Chain A, domain 2) in Nitric oxide synthase, endothelial in PDB 4imx.