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1210  structures 843  species 2  interactions 1560  sequences 41  architectures

Family: NO_synthase (PF02898)

Summary: Nitric oxide synthase, oxygenase domain

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

This is the Wikipedia entry entitled "Nitric oxide synthase". More...

Nitric oxide synthase Edit Wikipedia article

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This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Nitric oxide synthase, oxygenase domain Provide feedback

No Pfam abstract.

Literature references

  1. Crane BR, Arvai AS, Ghosh DK, Wu C, Getzoff ED, Stuehr DJ, Tainer JA; , Science 1998;279:2121-2126.: Structure of nitric oxide synthase oxygenase dimer with pterin and substrate. PUBMED:9516116 EPMC:9516116


External database links

This tab holds annotation information from the InterPro database.

InterPro entry 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.

Gene Ontology

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Domain organisation

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Alignments

We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the UniProtKB sequence database, the NCBI sequence database, and our metagenomics sequence database. More...

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We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.

  Seed
(70)
Full
(1560)
Representative proteomes UniProt
(4249)
NCBI
(6751)
Meta
(26)
RP15
(163)
RP35
(544)
RP55
(1205)
RP75
(1942)
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1Cannot generate PP/Heatmap alignments for seeds; no PP data available

Key: ✓ available, x not generated, not available.

Format an alignment

  Seed
(70)
Full
(1560)
Representative proteomes UniProt
(4249)
NCBI
(6751)
Meta
(26)
RP15
(163)
RP35
(544)
RP55
(1205)
RP75
(1942)
Alignment:
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Sequence:
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We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.

  Seed
(70)
Full
(1560)
Representative proteomes UniProt
(4249)
NCBI
(6751)
Meta
(26)
RP15
(163)
RP35
(544)
RP55
(1205)
RP75
(1942)
Raw Stockholm Download   Download   Download   Download   Download   Download   Download   Download   Download  
Gzipped Download   Download   Download   Download   Download   Download   Download   Download   Download  

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...

Trees

This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

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Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation View help on the curation process

Seed source: Structural domain
Previous IDs: none
Type: Domain
Sequence Ontology: SO:0000417
Author: Griffiths-Jones SR
Number in seed: 70
Number in full: 1560
Average length of the domain: 326.00 aa
Average identity of full alignment: 51 %
Average coverage of the sequence by the domain: 41.25 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 47079205 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 22.7 22.7
Trusted cut-off 23.5 23.2
Noise cut-off 20.0 19.6
Model length: 362
Family (HMM) version: 16
Download: download the raw HMM for this family

Species distribution

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Interactions

There are 2 interactions for this family. More...

NO_synthase CAT

Structures

For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the NO_synthase domain has been found. There are 1210 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.

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