Q54D73 · FHBB_DICDI
- ProteinFlavohemoprotein B
- GenefhbB
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids423 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Is involved in NO detoxification in an aerobic process, termed nitric oxide dioxygenase (NOD) reaction that utilizes O2 and NAD(P)H to convert NO to nitrate, which protects the cell from various noxious nitrogen compounds. Therefore, plays a central role in the inducible response to nitrosative stress.
In the presence of oxygen and NADH, it has NADH oxidase activity, which leads to the generation of superoxide and H2O2. Under anaerobic conditions, it also exhibits nitric oxide reductase and FAD reductase activities. However, all these reactions are much lower than NOD activity (By similarity).
Catalytic activity
- NADPH + 2 nitric oxide + 2 O2 = H+ + NADP+ + 2 nitrate
Cofactor
Protein has several cofactor binding sites:
Note: Binds 1 FAD per subunit.
Note: Binds 1 heme b group per subunit.
Features
Showing features for site, binding site, active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Site | 29 | Involved in heme-bound ligand stabilization and O-O bond activation | ||||
Sequence: Y | ||||||
Site | 82 | Influences the redox potential of the prosthetic heme and FAD groups | ||||
Sequence: K | ||||||
Binding site | 83 | Fe (UniProtKB | ChEBI) of heme b (UniProtKB | ChEBI); proximal binding residue | ||||
Sequence: H | ||||||
Active site | 93 | Charge relay system | ||||
Sequence: Y | ||||||
Active site | 135 | Charge relay system | ||||
Sequence: E | ||||||
Binding site | 188 | FAD (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 212-215 | FAD (UniProtKB | ChEBI) | ||||
Sequence: RHYS | ||||||
Binding site | 281-286 | NADP+ (UniProtKB | ChEBI) | ||||
Sequence: GVGINP | ||||||
Site | 399 | Influences the redox potential of the prosthetic heme and FAD groups | ||||
Sequence: E | ||||||
Binding site | 400-403 | FAD (UniProtKB | ChEBI) | ||||
Sequence: LFGP |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | phagocytic vesicle | |
Molecular Function | FAD binding | |
Molecular Function | heme binding | |
Molecular Function | metal ion binding | |
Molecular Function | nitric oxide dioxygenase NAD(P)H activity | |
Molecular Function | oxygen binding | |
Molecular Function | oxygen carrier activity | |
Biological Process | cellular response to glucose stimulus | |
Biological Process | cellular response to nitrosative stress | |
Biological Process | nitric oxide catabolic process | |
Biological Process | response to toxic substance |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameFlavohemoprotein B
- EC number
- Alternative names
Gene names
Organism names
- Strains
- Taxonomic lineageEukaryota > Amoebozoa > Evosea > Eumycetozoa > Dictyostelia > Dictyosteliales > Dictyosteliaceae > Dictyostelium
Accessions
- Primary accessionQ54D73
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000327850 | 1-423 | Flavohemoprotein B | |||
Sequence: MLSQKSIQIIKSTVPLLEKYGVEITSLFYKNMFEAQPQFLNIFNHSNQRNQKQPVALANTILQSAIHIEKLNEINLMPIVHKHVALGITPEMYPIVGAHLLGAMKTVMQDEATPEIMAAWTEAYRAVAQAFMDAEEDLYFETEEQIGGWKDTREFVVDRIEEETPLIKSFYFKAYDGKEIATYIPGQYITVKITLPGDGVDVPTDKMRTYVRHYSLSDKPNDEYYRISIKKELGKNTPNGIVSNHFHNNIKVGDVVPMSVPAGDFVVNNDSETPILLICGGVGINPLFSMLKETLVQQPDRKINFIFSTHCESSQPFKEELKQLEDDYKETGNLKINLVYSENQGHINKEIIEKYSTQHVDQAEIAETDVYICGPVPFMMQVNKDLLQLGFHKENVHYELFGPLTPVLEENQMLRGVKNIIEN |
Proteomic databases
Expression
Induction
By submerged conditions, in growing cells.
Developmental stage
Accumulates in macrocysts.
Interaction
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for domain, region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 1-136 | Globin | ||||
Sequence: MLSQKSIQIIKSTVPLLEKYGVEITSLFYKNMFEAQPQFLNIFNHSNQRNQKQPVALANTILQSAIHIEKLNEINLMPIVHKHVALGITPEMYPIVGAHLLGAMKTVMQDEATPEIMAAWTEAYRAVAQAFMDAEE | ||||||
Region | 149-423 | Reductase | ||||
Sequence: WKDTREFVVDRIEEETPLIKSFYFKAYDGKEIATYIPGQYITVKITLPGDGVDVPTDKMRTYVRHYSLSDKPNDEYYRISIKKELGKNTPNGIVSNHFHNNIKVGDVVPMSVPAGDFVVNNDSETPILLICGGVGINPLFSMLKETLVQQPDRKINFIFSTHCESSQPFKEELKQLEDDYKETGNLKINLVYSENQGHINKEIIEKYSTQHVDQAEIAETDVYICGPVPFMMQVNKDLLQLGFHKENVHYELFGPLTPVLEENQMLRGVKNIIEN | ||||||
Domain | 150-268 | FAD-binding FR-type | ||||
Sequence: KDTREFVVDRIEEETPLIKSFYFKAYDGKEIATYIPGQYITVKITLPGDGVDVPTDKMRTYVRHYSLSDKPNDEYYRISIKKELGKNTPNGIVSNHFHNNIKVGDVVPMSVPAGDFVVN |
Domain
Consists of two distinct domains; a N-terminal heme-containing oxygen-binding domain and a C-terminal reductase domain with binding sites for FAD and NAD(P)H.
Sequence similarities
Belongs to the globin family. Two-domain flavohemoproteins subfamily.
In the C-terminal section; belongs to the flavoprotein pyridine nucleotide cytochrome reductase family.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length423
- Mass (Da)48,206
- Last updated2005-05-24 v1
- Checksum3768C17E89D6D70C
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 366 | in Ref. 1; BAA83811 | ||||
Sequence: A → D |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AB025584 EMBL· GenBank· DDBJ | BAA83811.1 EMBL· GenBank· DDBJ | mRNA | ||
AAFI02000190 EMBL· GenBank· DDBJ | EAL61169.1 EMBL· GenBank· DDBJ | Genomic DNA |