The domain within your query sequence starts at position 129 and ends at position 491; the E-value for the NO_synthase domain shown below is 6.7e-189.



PFAM accession number:PF02898
Interpro abstract (IPR004030):

This entry represents the N-terminal of the nitric oxide synthases.

Nitric oxide synthase (EC (NOS) enzymes produce nitric oxide (NO) by catalysing a five-electron oxidation of a guanidino nitrogen of L-arginine (L-Arg). Oxidation of L-Arg to L-citrulline occurs via two successive monooxygenation reactions producing N(omega)-hydroxy-L-arginine as an intermediate. 2 mol of O(2) and 1.5 mol of NADPH are consumed per mole of NO formed [(PUBMED:8782597)].

Arginine-derived NO synthesis has been identified in mammals, fish, birds, invertebrates, plants, and bacteria [(PUBMED:8782597)]. Best studied are mammals, where three distinct genes encode NOS isozymes: neuronal (nNOS or NOS-1), cytokine-inducible (iNOS or NOS-2) and endothelial (eNOS or NOS-3) [(PUBMED:7510950)]. iNOS and nNOS are soluble and found predominantly in the cytosol, while eNOS is membrane associated. The enzymes exist as homodimers, each monomer consisting of two major domains: an N-terminal oxygenase domain, which belongs to the class of haem-thiolate proteins, and a C-terminal reductase domain, which is homologous to NADPH:P450 reductase (EC The interdomain linker between the oxygenase and reductase domains contains a calmodulin (CaM)-binding sequence. NOSs are the only enzymes known to simultaneously require five bound cofactors animal NOS isozymes are catalytically self-sufficient. The electron flow in the NO synthase reaction is: NADPH --> FAD --> FMN --> haem --> O(2).

eNOS localisation to endothelial membranes is mediated by cotranslational N-terminal myristoylation and post-translational palmitoylation [(PUBMED:9199168)]. The subcellular localisation of nNOS in skeletal muscle is mediated by anchoring of nNOS to dystrophin. nNOS contains an additional N-terminal domain, the PDZ domain [(PUBMED:7535955)]. Some bacteria, like Bacillus halodurans, Bacillus subtilis or Deinococcus radiodurans, contain homologues of NOS oxygenase domain.

GO process:nitric oxide biosynthetic process (GO:0006809), oxidation-reduction process (GO:0055114)
GO function:nitric-oxide synthase activity (GO:0004517)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry NO_synthase