Q6J1Z6 · AMNB_COMTE
- Protein2-aminophenol 1,6-dioxygenase subunit beta
- GenecnbCb
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids312 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Component of the 2-aminophenol 1,6-dioxygenase (APD) complex that catalyzes the ring fission of 2-aminophenol to produce 2-aminomuconic semialdehyde. CnbCb seems to be the catalytic subunit of the complex. Also active on other substrates such as 2-amino-5-chlorophenol (68% activity), protocatechuate (33% activity) and catechol (5% activity). Both 2-aminophenol and 2-amino-5-cholorophenol are likely native substrates for this dioxygenase which is involved in the reductive degradation pathway of both nitrobenzene (NB) and 4-chloronitrobenzene (4-CNB), allowing C.testosteroni strain CNB-1 to grow on these compounds as sole source of carbon, nitrogen, and energy.
Miscellaneous
Not active on 4-methylcatechol, 4-chlorocatechol, 2,4-dihydroxybenzoate, o-nitrophenol, p-nitrophenol or 4-nitrocatechol.
Catalytic activity
- 2-aminophenol + O2 = 2-aminomuconate 6-semialdehyde
Cofactor
Note: Binds 2 Fe2+ ions per APD complex. The iron ions are bound to the beta subunit.
Activity regulation
Complete loss of activity in the presence of Ni2+, Co2+, Cd2+, Zn2+ and hydrogen peroxide, however activity with hydrogen peroxide partially restored upon addition of excess ascorbate. Partially inhibited by Fe2+, Mg2+, Ca2+, Mn2+, Cu2+ and also by EDTA, at 2 mM concentration. Total activity inhibited in the presence of catechol or 4-nitrocatechol but completely restored after removal of catechol and addition of 2 mM Fe2+ and 5 mM ascorbate.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
0.89 μM | 2-aminophenol | |||||
17.1 μM | 2-aminophenol | |||||
0.77 μM | 2-amino-5-chlorophenol | |||||
6.84 μM | catechol | |||||
77.5 μM | oxygen | in the presence of 2-aminophenol | ||||
58.3 μM | oxygen | in the presence of catechol |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
44.6 μmol/min/mg | with 2-aminophenol as substrate | ||||
19 μmol/min/mg | with 2-aminophenol as substrate | ||||
19.3 μmol/min/mg | with 2-amino-5-chlorophenol as substrate | ||||
1.12 μmol/min/mg | with catechol as substrate |
Pathway
Xenobiotic degradation; nitrobenzene degradation.
Xenobiotic degradation; 4-chloronitrobenzene degradation.
Features
Showing features for binding site.
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | dioxygenase activity | |
Molecular Function | ferrous iron binding | |
Biological Process | catabolic process |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended name2-aminophenol 1,6-dioxygenase subunit beta
- EC number
- Alternative names
Gene names
Encoded on
- Plasmid pCNB1
Organism names
- Strain
- Taxonomic lineageBacteria > Pseudomonadota > Betaproteobacteria > Burkholderiales > Comamonadaceae > Comamonas
Accessions
- Primary accessionQ6J1Z6
- Secondary accessions
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 13 | Loss of enzyme activity. | ||||
Sequence: H → A | ||||||
Mutagenesis | 62 | Loss of enzyme activity. | ||||
Sequence: H → A | ||||||
Mutagenesis | 129 | Loss of enzyme activity. | ||||
Sequence: Y → F | ||||||
Mutagenesis | 195 | Loss of enzyme activity. | ||||
Sequence: H → Q | ||||||
Mutagenesis | 251 | Loss of enzyme activity. | ||||
Sequence: E → A |
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000422781 | 1-312 | 2-aminophenol 1,6-dioxygenase subunit beta | |||
Sequence: MQGEIIAGFLAPHPPHLVYGENPPQNEPRSQGGWEVLRWAYERARERLDAMKPDVLLVHSPHWITSVGHHFLGVPELSGKSVDPIFPNVFRYDFSLNVDVELAEACAEEGRKAGLVTKMMRNPKFRVDYGTITTLHLIRPQWDIPVVGISANNSPYYLNTKEGMSEMDVLGKATREAIRKTGRKAVLLASNTLSHWHFHEEPTIPEDMSKEYPATMAGYQWDIRMIELMRQGKTSEVFKLLPQFIDEAFAEVKSGAFTWMHAAMQYPELAAELFGYGTVIGTGNAVMEWDLRKAGLSMLGAADQKQRSAAVA |
Interaction
Subunit
The APD complex is a heterotetramer of 2 alpha (CnbCa) and 2 beta (CnbCb) subunits.
Structure
Sequence
- Sequence statusComplete
- Length312
- Mass (Da)35,040
- Last updated2013-06-26 v2
- ChecksumE05323C35EB8EFA4
Sequence caution
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 8 | in Ref. 1; AA sequence | ||||
Sequence: G → E |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AY605054 EMBL· GenBank· DDBJ | AAT35226.1 EMBL· GenBank· DDBJ | Genomic DNA | Different initiation | |
EF079106 EMBL· GenBank· DDBJ | ABB13577.1 EMBL· GenBank· DDBJ | Genomic DNA |