UniProtKB - P0ABK9 (NRFA_ECOLI)
Protein
Cytochrome c-552
Gene
nrfA
Organism
Escherichia coli (strain K12)
Status
Functioni
Catalyzes the reduction of nitrite to ammonia, consuming six electrons in the process (PubMed:9593308, PubMed:11863430, PubMed:18311941, PubMed:20629638). Has very low activity toward hydroxylamine (PubMed:11863430). Has even lower activity toward sulfite (PubMed:20629638). Sulfite reductase activity is maximal at neutral pH (By similarity).By similarity1 Publication4 Publications
Catalytic activityi
- EC:1.7.2.24 Publications
Cofactori
Protein has several cofactor binding sites:- Ca2+4 PublicationsNote: Binds 1 Ca2+ ion per monomer.4 Publications
- heme6 PublicationsNote: Binds 5 heme groups covalently per monomer.4 Publications
Activity regulationi
Subject to competitive inhibition by sulfite.1 Publication
Kineticsi
- KM=28 µM for nitrite1 Publication
- KM=30 µM for nitrite1 Publication
- KM=22 µM for nitrite1 Publication
- KM=70 µM for sulfite1 Publication
- KM=30 mM for hydroxylamine1 Publication
: nitrate reduction (assimilation) Pathwayi
This protein is involved in the pathway nitrate reduction (assimilation), which is part of Nitrogen metabolism.1 PublicationView all proteins of this organism that are known to be involved in the pathway nitrate reduction (assimilation) and in Nitrogen metabolism.
Sites
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Metal bindingi | 94 | Iron (heme 3 axial ligand)Combined sources | 1 | |
Binding sitei | 122 | Heme 1; covalentCombined sources | 1 | |
Binding sitei | 125 | Heme 1; covalentCombined sources | 1 | |
Metal bindingi | 126 | Iron (heme 1 axial ligand)Combined sources | 1 | |
Binding sitei | 160 | Heme 2; covalentCombined sources | 1 | |
Binding sitei | 163 | Heme 2; covalentCombined sources | 1 | |
Metal bindingi | 164 | Iron (heme 2 axial ligand)Combined sources | 1 | |
Binding sitei | 209 | Heme 3; covalentCombined sources | 1 | |
Binding sitei | 212 | Heme 3; covalentCombined sources | 1 | |
Metal bindingi | 213 | Iron (heme 3 axial ligand)Combined sources | 1 | |
Metal bindingi | 215 | CalciumCombined sources | 1 | |
Metal bindingi | 216 | Calcium; via carbonyl oxygenCombined sources | 1 | |
Binding sitei | 216 | SubstrateCurated | 1 | |
Metal bindingi | 261 | Calcium; via carbonyl oxygenCombined sources | 1 | |
Metal bindingi | 263 | CalciumCombined sources | 1 | |
Binding sitei | 264 | SubstrateCurated | 1 | |
Metal bindingi | 275 | Iron (heme 5 axial ligand)Combined sources | 1 | |
Binding sitei | 282 | Heme 4; covalentCombined sources | 1 | |
Binding sitei | 285 | Heme 4; covalentCombined sources | 1 | |
Metal bindingi | 286 | Iron (heme 4 axial ligand)Combined sources | 1 | |
Metal bindingi | 301 | Iron (heme 2 axial ligand)Combined sources | 1 | |
Binding sitei | 314 | Heme 5; covalentCombined sources | 1 | |
Binding sitei | 317 | Heme 5; covalentCombined sources | 1 | |
Metal bindingi | 318 | Iron (heme 5 axial ligand)Combined sources | 1 | |
Metal bindingi | 393 | Iron (heme 4 axial ligand)Combined sources | 1 |
GO - Molecular functioni
- calcium ion binding Source: UniProtKB-UniRule
- heme binding Source: EcoCyc
- iron ion binding Source: UniProtKB-UniRule
- nitric oxide reductase activity Source: CACAO
- nitrite reductase (cytochrome, ammonia-forming) activity Source: EcoCyc
GO - Biological processi
- anaerobic electron transport chain Source: EcoCyc
- nitrate assimilation Source: UniProtKB-UniPathway
Keywordsi
Molecular function | Oxidoreductase |
Biological process | Electron transport, Transport |
Ligand | Calcium, Heme, Iron, Metal-binding |
Enzyme and pathway databases
BioCyci | EcoCyc:CYTOCHROMEC552-MONOMER MetaCyc:CYTOCHROMEC552-MONOMER |
BRENDAi | 1.7.2.2, 2026 |
SABIO-RKi | P0ABK9 |
UniPathwayi | UPA00653 |
Names & Taxonomyi
Protein namesi | Recommended name: Cytochrome c-5521 Publication (EC:1.7.2.24 Publications)Alternative name(s): Ammonia-forming cytochrome c nitrite reductase Short name: Cytochrome c nitrite reductase1 Publication |
Gene namesi | Name:nrfA Ordered Locus Names:b4070, JW4031 |
Organismi | Escherichia coli (strain K12) |
Taxonomic identifieri | 83333 [NCBI] |
Taxonomic lineagei | Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacterales › Enterobacteriaceae › Escherichia › |
Proteomesi |
|
Subcellular locationi
Other locations
- Periplasm 3 Publications
Other locations
- outer membrane-bounded periplasmic space Source: EcoCyc
Keywords - Cellular componenti
PeriplasmPathology & Biotechi
Mutagenesis
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Mutagenesisi | 126 | K → H, I or L: Almost complete loss of nitrite reductase activity. 1 Publication | 1 | |
Mutagenesisi | 263 | Q → E: Increases affinity for nitrite without changing Vmax. 1 Publication | 1 |
Chemistry databases
DrugBanki | DB03317, Ferroheme C |
PTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Signal peptidei | 1 – 26 | 1 PublicationAdd BLAST | 26 | |
ChainiPRO_0000006578 | 27 – 478 | Cytochrome c-552Add BLAST | 452 |
Proteomic databases
jPOSTi | P0ABK9 |
PaxDbi | P0ABK9 |
PRIDEi | P0ABK9 |
Expressioni
Inductioni
Full induction attained in the presence of nitrite. Subject to glucose and nitrate repression.1 Publication
Interactioni
Subunit structurei
Protein-protein interaction databases
BioGRIDi | 4259405, 27 interactors |
DIPi | DIP-36021N |
IntActi | P0ABK9, 3 interactors |
STRINGi | 511145.b4070 |
Structurei
Secondary structure
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details3D structure databases
SMRi | P0ABK9 |
ModBasei | Search... |
PDBe-KBi | Search... |
Miscellaneous databases
EvolutionaryTracei | P0ABK9 |
Family & Domainsi
Sequence similaritiesi
Belongs to the cytochrome c-552 family.Curated
Keywords - Domaini
SignalPhylogenomic databases
eggNOGi | COG3303, Bacteria |
HOGENOMi | CLU_035040_1_0_6 |
InParanoidi | P0ABK9 |
PhylomeDBi | P0ABK9 |
Family and domain databases
CDDi | cd00548, NrfA-like, 1 hit |
HAMAPi | MF_01182, Cytochrom_C552, 1 hit |
InterProi | View protein in InterPro IPR003321, Cyt_c552 IPR017570, Cyt_c_NO2Rdtase_formate-dep IPR011031, Multihaem_cyt IPR036280, Multihaem_cyt_sf |
PANTHERi | PTHR30633, PTHR30633, 1 hit |
Pfami | View protein in Pfam PF02335, Cytochrom_C552, 1 hit |
PIRSFi | PIRSF000243, Cyt_c552, 1 hit |
SUPFAMi | SSF48695, SSF48695, 1 hit |
TIGRFAMsi | TIGR03152, cyto_c552_HCOOH, 1 hit |
PROSITEi | View protein in PROSITE PS51008, MULTIHEME_CYTC, 1 hit |
i Sequence
Sequence statusi: Complete.
: The displayed sequence is further processed into a mature form. Sequence processingi
P0ABK9-1 [UniParc]FASTAAdd to basket
10 20 30 40 50
MTRIKINARR IFSLLIPFFF FTSVHAEQTA APAKPVTVEA KNETFAPQHP
60 70 80 90 100
DQYLSWKATS EQSERVDALA EDPRLVILWA GYPFSRDYNK PRGHAFAVTD
110 120 130 140 150
VRETLRTGAP KNAEDGPLPM ACWSCKSPDV ARLIQKDGED GYFHGKWARG
160 170 180 190 200
GPEIVNNLGC ADCHNTASPE FAKGKPELTL SRPYAARAME AIGKPFEKAG
210 220 230 240 250
RFDQQSMVCG QCHVEYYFDG KNKAVKFPWD DGMKVENMEQ YYDKIAFSDW
260 270 280 290 300
TNSLSKTPML KAQHPEYETW TAGIHGKNNV TCIDCHMPKV QNAEGKLYTD
310 320 330 340 350
HKIGNPFDNF AQTCANCHTQ DKAALQKVVA ERKQSINDLK IKVEDQLVHA
360 370 380 390 400
HFEAKAALDA GATEAEMKPI QDDIRHAQWR WDLAIASHGI HMHAPEEGLR
410 420 430 440 450
MLGTAMDKAA DARTKLARLL ATKGITHEIQ IPDISTKEKA QQAIGLNMEQ
460 470
IKAEKQDFIK TVIPQWEEQA RKNGLLSQ
Mass spectrometryi
Molecular mass is 53590 Da. Determined by MALDI. 1 Publication
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | X72298 Genomic DNA Translation: CAA51048.1 U00006 Genomic DNA Translation: AAC43164.1 U00096 Genomic DNA Translation: AAC77040.1 AP009048 Genomic DNA Translation: BAE78072.1 |
PIRi | S39590 |
RefSeqi | NP_418494.1, NC_000913.3 WP_000196875.1, NZ_STEB01000014.1 |
Genome annotation databases
EnsemblBacteriai | AAC77040; AAC77040; b4070 BAE78072; BAE78072; BAE78072 |
GeneIDi | 58459647 948571 |
KEGGi | ecj:JW4031 eco:b4070 |
PATRICi | fig|1411691.4.peg.2634 |
Similar proteinsi
Cross-referencesi
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | X72298 Genomic DNA Translation: CAA51048.1 U00006 Genomic DNA Translation: AAC43164.1 U00096 Genomic DNA Translation: AAC77040.1 AP009048 Genomic DNA Translation: BAE78072.1 |
PIRi | S39590 |
RefSeqi | NP_418494.1, NC_000913.3 WP_000196875.1, NZ_STEB01000014.1 |
3D structure databases
Select the link destinations: PDBei RCSB PDBi PDBji Links Updated | PDB entry | Method | Resolution (Å) | Chain | Positions | PDBsum |
1GU6 | X-ray | 2.50 | A/C/E/G | 27-478 | [»] | |
2RDZ | X-ray | 1.74 | A/B/C/D | 27-478 | [»] | |
2RF7 | X-ray | 2.04 | A/B/C/D | 37-477 | [»] | |
3L1T | X-ray | 2.30 | A/B/C/D | 27-478 | [»] | |
3TOR | X-ray | 2.00 | A/B/C/D | 27-478 | [»] | |
4WJY | X-ray | 2.15 | A/B | 27-478 | [»] | |
SMRi | P0ABK9 | |||||
ModBasei | Search... | |||||
PDBe-KBi | Search... |
Protein-protein interaction databases
BioGRIDi | 4259405, 27 interactors |
DIPi | DIP-36021N |
IntActi | P0ABK9, 3 interactors |
STRINGi | 511145.b4070 |
Chemistry databases
DrugBanki | DB03317, Ferroheme C |
Proteomic databases
jPOSTi | P0ABK9 |
PaxDbi | P0ABK9 |
PRIDEi | P0ABK9 |
Genome annotation databases
EnsemblBacteriai | AAC77040; AAC77040; b4070 BAE78072; BAE78072; BAE78072 |
GeneIDi | 58459647 948571 |
KEGGi | ecj:JW4031 eco:b4070 |
PATRICi | fig|1411691.4.peg.2634 |
Organism-specific databases
EchoBASEi | EB1729 |
Phylogenomic databases
eggNOGi | COG3303, Bacteria |
HOGENOMi | CLU_035040_1_0_6 |
InParanoidi | P0ABK9 |
PhylomeDBi | P0ABK9 |
Enzyme and pathway databases
UniPathwayi | UPA00653 |
BioCyci | EcoCyc:CYTOCHROMEC552-MONOMER MetaCyc:CYTOCHROMEC552-MONOMER |
BRENDAi | 1.7.2.2, 2026 |
SABIO-RKi | P0ABK9 |
Miscellaneous databases
EvolutionaryTracei | P0ABK9 |
PROi | PR:P0ABK9 |
Family and domain databases
CDDi | cd00548, NrfA-like, 1 hit |
HAMAPi | MF_01182, Cytochrom_C552, 1 hit |
InterProi | View protein in InterPro IPR003321, Cyt_c552 IPR017570, Cyt_c_NO2Rdtase_formate-dep IPR011031, Multihaem_cyt IPR036280, Multihaem_cyt_sf |
PANTHERi | PTHR30633, PTHR30633, 1 hit |
Pfami | View protein in Pfam PF02335, Cytochrom_C552, 1 hit |
PIRSFi | PIRSF000243, Cyt_c552, 1 hit |
SUPFAMi | SSF48695, SSF48695, 1 hit |
TIGRFAMsi | TIGR03152, cyto_c552_HCOOH, 1 hit |
PROSITEi | View protein in PROSITE PS51008, MULTIHEME_CYTC, 1 hit |
ProtoNeti | Search... |
MobiDBi | Search... |
Entry informationi
Entry namei | NRFA_ECOLI | |
Accessioni | P0ABK9Primary (citable) accession number: P0ABK9 Secondary accession number(s): P32050, Q2M6N4 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | November 8, 2005 |
Last sequence update: | November 8, 2005 | |
Last modified: | April 7, 2021 | |
This is version 127 of the entry and version 1 of the sequence. See complete history. | ||
Entry statusi | Reviewed (UniProtKB/Swiss-Prot) | |
Annotation program | Prokaryotic Protein Annotation Program |
Miscellaneousi
Keywords - Technical termi
3D-structure, Direct protein sequencing, Reference proteomeDocuments
- PATHWAY comments
Index of metabolic and biosynthesis pathways - PDB cross-references
Index of Protein Data Bank (PDB) cross-references - SIMILARITY comments
Index of protein domains and families