Q94734 · NP4_RHOPR
- ProteinNitrophorin-4
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids205 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Heme-based protein that delivers nitric oxide gas (NO) to the victim while feeding, resulting in vasodilation and inhibition of platelet aggregation. Also binds tightly to histamine, which is released by the host to induce wound healing. NO release is pH dependent and linked to loop dynamics.
Miscellaneous
Superposition of the structures of NP4 in the presence of ammonia or nitrite shows a conformational change of the protein upon NO2- binding.
Catalytic activity
- 3 nitrite + 2 H+ = 2 nitric oxide + nitrate + H2O
Cofactor
Note: Binds 1 heme b (iron(II)-protoporphyrin IX) group per subunit.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Binding site | 80 | Fe (UniProtKB | ChEBI) of heme (UniProtKB | ChEBI); proximal binding residue | |||
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | extracellular region | |
Molecular Function | histamine binding | |
Molecular Function | metal ion binding | |
Molecular Function | nitric oxide binding | |
Molecular Function | oxidoreductase activity | |
Biological Process | vasodilation |
Keywords
- Molecular function
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameNitrophorin-4
- EC number
- Short namesNP4
- Alternative names
Organism names
- Taxonomic lineageEukaryota > Metazoa > Ecdysozoa > Arthropoda > Hexapoda > Insecta > Pterygota > Neoptera > Paraneoptera > Hemiptera > Heteroptera > Panheteroptera > Cimicomorpha > Reduviidae > Triatominae > Rhodnius
Accessions
- Primary accessionQ94734
Proteomes
Organism-specific databases
Subcellular Location
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Mutagenesis | 51 | Loss of NO-induced conformational change and strongly reduced pH dependence for NO release. Stabilization of the ferric-NO heme center and decreased nitrite disproportionation. | |||
Mutagenesis | 76 | Stabilization of the ferric-NO heme center. | |||
Mutagenesis | 142 | No effect on NO-induced conformational change or on pH dependence for NO release. Increased NO association rates. | |||
Mutagenesis | 150-151 | Loss of NO-induced conformational change and loss of pH dependence for NO release. | |||
Mutagenesis | 151 | Coordination of the heme iron center and inhibition of nitrite disproportionation. | |||
PTM/Processing
Features
Showing features for signal, chain, disulfide bond.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Signal | 1-21 | ||||
Chain | PRO_0000021826 | 22-205 | Nitrophorin-4 | ||
Disulfide bond | 23↔143 | ||||
Disulfide bond | 62↔192 | ||||
Keywords
- PTM
Expression
Tissue specificity
Expressed by the salivary glands.
Interaction
Protein-protein interaction databases
Structure
Family & Domains
Sequence similarities
Belongs to the calycin superfamily. Nitrophorin family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
- Length205
- Mass (Da)22,406
- Last updated1997-02-01 v1
- MD5 ChecksumF5977553120DACD987D302FA0A1656E7
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
U70584 EMBL· GenBank· DDBJ | AAB09590.1 EMBL· GenBank· DDBJ | mRNA |