Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Nitrate/nitrite sensor protein NarX

Gene

narX

Organism
Escherichia coli (strain K12)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Acts as a sensor for nitrate/nitrite and transduces signal of nitrate availability to the NarL protein and of both nitrate/nitrite to the NarP protein. NarX probably activates NarL and NarP by phosphorylation in the presence of nitrate. NarX also plays a negative role in controlling NarL activity, probably through dephosphorylation in the absence of nitrate.

Catalytic activityi

ATP + protein L-histidine = ADP + protein N-phospho-L-histidine.

GO - Molecular functioni

  • ATP binding Source: UniProtKB-KW
  • phosphoprotein phosphatase activity Source: EcoCyc
  • phosphorelay sensor kinase activity Source: EcoCyc

GO - Biological processi

  • cellular response to DNA damage stimulus Source: EcoliWiki
  • cellular response to nitrate Source: EcoCyc
  • cellular response to nitrite Source: EcoCyc
  • nitrate assimilation Source: UniProtKB-KW
  • phosphorelay signal transduction system Source: EcoCyc
  • protein autophosphorylation Source: EcoCyc
Complete GO annotation...

Keywords - Molecular functioni

Kinase, Transferase

Keywords - Biological processi

Nitrate assimilation, Two-component regulatory system

Keywords - Ligandi

ATP-binding, Nucleotide-binding

Enzyme and pathway databases

BioCyciEcoCyc:NARX-MONOMER.
ECOL316407:JW1213-MONOMER.
BRENDAi2.7.13.3. 2026.

Names & Taxonomyi

Protein namesi
Recommended name:
Nitrate/nitrite sensor protein NarX (EC:2.7.13.3)
Gene namesi
Name:narX
Synonyms:narR
Ordered Locus Names:b1222, JW1213
OrganismiEscherichia coli (strain K12)
Taxonomic identifieri83333 [NCBI]
Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacterialesEnterobacteriaceaeEscherichia
Proteomesi
  • UP000000318 Componenti: Chromosome
  • UP000000625 Componenti: Chromosome

Organism-specific databases

EcoGeneiEG10646. narX.

Subcellular locationi

Topology

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Topological domaini1 – 1414CytoplasmicSequence analysisAdd
BLAST
Transmembranei15 – 3723HelicalSequence analysisAdd
BLAST
Topological domaini38 – 151114PeriplasmicSequence analysisAdd
BLAST
Transmembranei152 – 17423HelicalSequence analysisAdd
BLAST
Topological domaini175 – 598424CytoplasmicSequence analysisAdd
BLAST

GO - Cellular componenti

  • integral component of membrane Source: UniProtKB-KW
  • intracellular Source: GOC
  • plasma membrane Source: EcoCyc
Complete GO annotation...

Keywords - Cellular componenti

Cell inner membrane, Cell membrane, Membrane

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 598598Nitrate/nitrite sensor protein NarXPRO_0000074812Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei399 – 3991Phosphohistidine; by autocatalysisPROSITE-ProRule annotation

Keywords - PTMi

Phosphoprotein

Proteomic databases

PaxDbiP0AFA2.
PRIDEiP0AFA2.

Interactioni

Protein-protein interaction databases

BioGridi4263270. 7 interactions.
DIPiDIP-35785N.
IntActiP0AFA2. 4 interactions.
STRINGi511145.b1222.

Structurei

Secondary structure

1
598
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Helixi43 – 6220Combined sources
Helixi68 – 703Combined sources
Helixi71 – 8111Combined sources
Helixi84 – 9310Combined sources
Helixi96 – 10813Combined sources
Helixi110 – 1167Combined sources
Helixi120 – 1223Combined sources
Helixi124 – 15027Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
3EZHX-ray1.70A/B38-151[»]
3EZIX-ray1.70A/B/C/D42-148[»]
ProteinModelPortaliP0AFA2.
SMRiP0AFA2. Positions 42-151, 380-581.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP0AFA2.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini176 – 22853HAMPPROSITE-ProRule annotationAdd
BLAST
Domaini393 – 587195Histidine kinasePROSITE-ProRule annotationAdd
BLAST

Sequence similaritiesi

Contains 1 HAMP domain.PROSITE-ProRule annotation
Contains 1 histidine kinase domain.PROSITE-ProRule annotation

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiENOG4105BZU. Bacteria.
ENOG410XNMH. LUCA.
HOGENOMiHOG000275465.
InParanoidiP0AFA2.
KOiK07673.
OMAiAIDQKTE.
PhylomeDBiP0AFA2.

Family and domain databases

CDDicd06225. HAMP. 1 hit.
Gene3Di3.30.565.10. 1 hit.
InterProiIPR003660. HAMP_dom.
IPR003594. HATPase_C.
IPR005467. His_kinase_dom.
IPR029095. NarX-like_N.
IPR016380. Sig_transdc_His_kin_NarX/NarQ.
IPR011712. Sig_transdc_His_kin_sub3_dim/P.
[Graphical view]
PfamiPF00672. HAMP. 1 hit.
PF02518. HATPase_c. 1 hit.
PF07730. HisKA_3. 1 hit.
PF13675. PilJ. 1 hit.
[Graphical view]
PIRSFiPIRSF003167. STHK_NarX/NarQ. 1 hit.
SMARTiSM00304. HAMP. 1 hit.
SM00387. HATPase_c. 1 hit.
[Graphical view]
SUPFAMiSSF55874. SSF55874. 1 hit.
PROSITEiPS50885. HAMP. 1 hit.
PS50109. HIS_KIN. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

P0AFA2-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MLKRCLSPLT LVNQVALIVL LSTAIGLAGM AVSGWLVQGV QGSAHAINKA
60 70 80 90 100
GSLRMQSYRL LAAVPLSEKD KPLIKEMEQT AFSAELTRAA ERDGQLAQLQ
110 120 130 140 150
GLQDYWRNEL IPALMRAQNR ETVSADVSQF VAGLDQLVSG FDRTTEMRIE
160 170 180 190 200
TVVLVHRVMA VFMALLLVFT IIWLRARLLQ PWRQLLAMAS AVSHRDFTQR
210 220 230 240 250
ANISGRNEMA MLGTALNNMS AELAESYAVL EQRVQEKTAG LEHKNQILSF
260 270 280 290 300
LWQANRRLHS RAPLCERLSP VLNGLQNLTL LRDIELRVYD TDDEENHQEF
310 320 330 340 350
TCQPDMTCDD KGCQLCPRGV LPVGDRGTTL KWRLADSHTQ YGILLATLPQ
360 370 380 390 400
GRHLSHDQQQ LVDTLVEQLT ATLALDRHQE RQQQLIVMEE RATIARELHD
410 420 430 440 450
SIAQSLSCMK MQVSCLQMQG DALPESSREL LSQIRNELNA SWAQLRELLT
460 470 480 490 500
TFRLQLTEPG LRPALEASCE EYSAKFGFPV KLDYQLPPRL VPSHQAIHLL
510 520 530 540 550
QIAREALSNA LKHSQASEVV VTVAQNDNQV KLTVQDNGCG VPENAIRSNH
560 570 580 590
YGMIIMRDRA QSLRGDCRVR RRESGGTEVV VTFIPEKTFT DVQGDTHE
Length:598
Mass (Da):67,084
Last modified:December 20, 2005 - v1
Checksum:i886BA0FC2C8F3C3E
GO

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti42 – 5211GSAHAINKAGS → AAPMRSTKRDA (PubMed:2657652).CuratedAdd
BLAST
Sequence conflicti42 – 5211GSAHAINKAGS → AAPMRSTKRDA (PubMed:2668029).CuratedAdd
BLAST
Sequence conflicti374 – 3741A → G in AAA24198 (PubMed:2649492).Curated

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X13360 Genomic DNA. Translation: CAA31741.1.
U00096 Genomic DNA. Translation: AAC74306.1.
AP009048 Genomic DNA. Translation: BAA36090.1.
X15996 Genomic DNA. Translation: CAA34125.1.
M24910 Genomic DNA. Translation: AAA24198.1.
X65715 Genomic DNA. Translation: CAA46631.1.
X69189 Genomic DNA. Translation: CAA48934.1.
PIRiS26137. RGECNX.
RefSeqiNP_415740.1. NC_000913.3.
WP_000918073.1. NZ_LN832404.1.

Genome annotation databases

EnsemblBacteriaiAAC74306; AAC74306; b1222.
BAA36090; BAA36090; BAA36090.
GeneIDi945788.
KEGGiecj:JW1213.
eco:b1222.
PATRICi32117702. VBIEscCol129921_1273.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X13360 Genomic DNA. Translation: CAA31741.1.
U00096 Genomic DNA. Translation: AAC74306.1.
AP009048 Genomic DNA. Translation: BAA36090.1.
X15996 Genomic DNA. Translation: CAA34125.1.
M24910 Genomic DNA. Translation: AAA24198.1.
X65715 Genomic DNA. Translation: CAA46631.1.
X69189 Genomic DNA. Translation: CAA48934.1.
PIRiS26137. RGECNX.
RefSeqiNP_415740.1. NC_000913.3.
WP_000918073.1. NZ_LN832404.1.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
3EZHX-ray1.70A/B38-151[»]
3EZIX-ray1.70A/B/C/D42-148[»]
ProteinModelPortaliP0AFA2.
SMRiP0AFA2. Positions 42-151, 380-581.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi4263270. 7 interactions.
DIPiDIP-35785N.
IntActiP0AFA2. 4 interactions.
STRINGi511145.b1222.

Proteomic databases

PaxDbiP0AFA2.
PRIDEiP0AFA2.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaiAAC74306; AAC74306; b1222.
BAA36090; BAA36090; BAA36090.
GeneIDi945788.
KEGGiecj:JW1213.
eco:b1222.
PATRICi32117702. VBIEscCol129921_1273.

Organism-specific databases

EchoBASEiEB0640.
EcoGeneiEG10646. narX.

Phylogenomic databases

eggNOGiENOG4105BZU. Bacteria.
ENOG410XNMH. LUCA.
HOGENOMiHOG000275465.
InParanoidiP0AFA2.
KOiK07673.
OMAiAIDQKTE.
PhylomeDBiP0AFA2.

Enzyme and pathway databases

BioCyciEcoCyc:NARX-MONOMER.
ECOL316407:JW1213-MONOMER.
BRENDAi2.7.13.3. 2026.

Miscellaneous databases

EvolutionaryTraceiP0AFA2.
PROiP0AFA2.

Family and domain databases

CDDicd06225. HAMP. 1 hit.
Gene3Di3.30.565.10. 1 hit.
InterProiIPR003660. HAMP_dom.
IPR003594. HATPase_C.
IPR005467. His_kinase_dom.
IPR029095. NarX-like_N.
IPR016380. Sig_transdc_His_kin_NarX/NarQ.
IPR011712. Sig_transdc_His_kin_sub3_dim/P.
[Graphical view]
PfamiPF00672. HAMP. 1 hit.
PF02518. HATPase_c. 1 hit.
PF07730. HisKA_3. 1 hit.
PF13675. PilJ. 1 hit.
[Graphical view]
PIRSFiPIRSF003167. STHK_NarX/NarQ. 1 hit.
SMARTiSM00304. HAMP. 1 hit.
SM00387. HATPase_c. 1 hit.
[Graphical view]
SUPFAMiSSF55874. SSF55874. 1 hit.
PROSITEiPS50885. HAMP. 1 hit.
PS50109. HIS_KIN. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiNARX_ECOLI
AccessioniPrimary (citable) accession number: P0AFA2
Secondary accession number(s): P10956
Entry historyi
Integrated into UniProtKB/Swiss-Prot: December 20, 2005
Last sequence update: December 20, 2005
Last modified: September 7, 2016
This is version 94 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. Escherichia coli
    Escherichia coli (strain K12): entries and cross-references to EcoGene
  2. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  3. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.