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Protein

Quinone reductase

Gene

chrR

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

Functioni

Catalyzes the reduction of quinones (PubMed:14766567). Acts by simultaneous two-electron transfer, avoiding formation of highly reactive semiquinone intermediates and producing quinols that promote tolerance of H2O2. Quinone reduction is probably the primary biological role of ChrR (By similarity). Can also reduce toxic chromate to insoluble and less toxic Cr3+. Catalyzes the transfer of three electrons to Cr6+ producing Cr3+ and one electron to molecular oxygen without producing the toxic Cr5+ species and only producing a minimal amount of reactive oxygen species (ROS). Chromate reduction protects the cell against chromate toxicity, but is likely a secondary activity (PubMed:14766567, PubMed:17088379, PubMed:22558308). Can also reduce potassium ferricyanide, 2,6-dichloroindophenol, V5+, Mo6+, methylene blue, cytochrome c and U6+ (PubMed:14766567, PubMed:17088379). During chromate reduction, is able to use both NAD or NADP equally well (PubMed:14766567).By similarity3 Publications

Catalytic activityi

NAD(P)H + a quinone = NAD(P)+ + a hydroquinone.1 Publication
2 NAD(P)H + Cr6+ + O2 = 2 NAD(P)+ + Cr3+ + superoxide.3 Publications

Cofactori

FMN2 PublicationsNote: Binds 1 FMN per subunit.1 Publication

Enzyme regulationi

May be inhibited by divalent cations.1 Publication

Kineticsi

kcat is 3.7 sec(-1) with chromate as substrate (at pH 5 and 35 degrees Celsius) (PubMed:14766567). kcat is 29 sec(-1) with uranyl as substrate (at pH 7 and 37 degrees Celsius) (PubMed:17088379). kcat is 30 sec(-1) with chromate as substrate (at pH 7 and 37 degrees Celsius) (PubMed:17088379).2 Publications
  1. KM=108 µM for uranyl (at pH 7 and 37 degrees Celsius)1 Publication
  2. KM=200 µM for chromate (at pH 5 and 35 degrees Celsius)1 Publication
  3. KM=376 µM for chromate (at pH 7 and 37 degrees Celsius)1 Publication
  1. Vmax=5 µmol/min/mg enzyme with chromate as substrate (at pH 5 and 35 degrees Celsius)1 Publication
  2. Vmax=213 nmol/min/mg enzyme with uranyl as substrate (at pH 7 and 37 degrees Celsius)1 Publication
  3. Vmax=295 nmol/min/mg enzyme with chromate as substrate (at pH 7 and 37 degrees Celsius)1 Publication

pH dependencei

Optimum pH is 5.1 Publication

Temperature dependencei

Optimum temperature is 35 degrees Celsius.1 Publication

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Binding sitei117FMN1 Publication1

Regions

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Nucleotide bindingi13 – 20FMN1 Publication8
Nucleotide bindingi82 – 85FMN1 Publication4

GO - Molecular functioni

  • FMN binding Source: EcoCyc
  • FMN reductase (NADPH) activity Source: GO_Central
  • NAD(P)H dehydrogenase (quinone) activity Source: UniProtKB-EC
  • oxidoreductase activity Source: EcoCyc

GO - Biological processi

  • xenobiotic metabolic process Source: EcoCyc

Keywordsi

Molecular functionOxidoreductase
LigandFlavoprotein, FMN, NAD, NADP

Enzyme and pathway databases

BioCyciEcoCyc:EG11723-MONOMER.
MetaCyc:EG11723-MONOMER.

Names & Taxonomyi

Protein namesi
Recommended name:
Quinone reductaseCurated (EC:1.6.5.21 Publication)
Alternative name(s):
Chromate reductaseCurated (EC:1.6.-.-3 Publications)
Short name:
CHRR
NAD(P)H dehydrogenase (quinone)Curated
Gene namesi
Name:chrR
Synonyms:yieF
Ordered Locus Names:b3713, JW3691
OrganismiEscherichia coli (strain K12)
Taxonomic identifieri83333 [NCBI]
Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacteralesEnterobacteriaceaeEscherichia
Proteomesi
  • UP000000318 Componenti: Chromosome
  • UP000000625 Componenti: Chromosome

Organism-specific databases

EcoGeneiEG11723. chrR.

Subcellular locationi

GO - Cellular componenti

  • cytosol Source: EcoCyc

Pathology & Biotechi

Disruption phenotypei

Cells lacking this gene show an increased sensitivity to chromate.1 Publication

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi85Y → N: Improves chromate reductase activity compared to the wild-type enzyme. 1 Publication1
Mutagenesisi125R → M: Improves chromate reductase activity compared to the wild-type enzyme. 1 Publication1
Mutagenesisi128Y → N: Improves chromate reductase activity compared to the wild-type enzyme. Increase of the affinity binding and catalytic efficiency for both chromate and uranyl. 2 Publications1
Mutagenesisi146E → T: Improves chromate reductase activity compared to the wild-type enzyme. 1 Publication1

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00001605961 – 188Quinone reductaseAdd BLAST188

Proteomic databases

PaxDbiP0AGE6.
PRIDEiP0AGE6.

Expressioni

Inductioni

Induced by both chromate and the stationary phase.1 Publication

Interactioni

Subunit structurei

Homotetramer. Dimer of dimers. The tetrameric configuration has a central role in chromate reductase activity.1 Publication

Protein-protein interaction databases

BioGridi4262171. 9 interactors.
DIPiDIP-36041N.
IntActiP0AGE6. 2 interactors.
STRINGi316385.ECDH10B_3900.

Structurei

Secondary structure

1188
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Beta strandi5 – 11Combined sources7
Helixi19 – 26Combined sources8
Helixi27 – 29Combined sources3
Beta strandi35 – 39Combined sources5
Helixi51 – 56Combined sources6
Helixi61 – 72Combined sources12
Beta strandi73 – 80Combined sources8
Helixi89 – 99Combined sources11
Turni105 – 108Combined sources4
Beta strandi110 – 116Combined sources7
Turni120 – 123Combined sources4
Helixi124 – 136Combined sources13
Beta strandi147 – 149Combined sources3
Helixi152 – 155Combined sources4
Turni158 – 161Combined sources4
Helixi166 – 182Combined sources17

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
3SVLX-ray2.20A/B3-188[»]
ProteinModelPortaliP0AGE6.
SMRiP0AGE6.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Belongs to the SsuE family.Curated

Phylogenomic databases

eggNOGiENOG4108YYH. Bacteria.
COG0431. LUCA.
HOGENOMiHOG000263119.
InParanoidiP0AGE6.
KOiK19784.
PhylomeDBiP0AGE6.

Family and domain databases

Gene3Di3.40.50.360. 1 hit.
InterProiView protein in InterPro
IPR029039. Flavoprotein-like_sf.
IPR005025. FMN_Rdtase-like.
PfamiView protein in Pfam
PF03358. FMN_red. 1 hit.
SUPFAMiSSF52218. SSF52218. 1 hit.

Sequencei

Sequence statusi: Complete.

P0AGE6-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MSEKLQVVTL LGSLRKGSFN GMVARTLPKI APASMEVNAL PSIADIPLYD
60 70 80 90 100
ADVQQEEGFP ATVEALAEQI RQADGVVIVT PEYNYSVPGG LKNAIDWLSR
110 120 130 140 150
LPDQPLAGKP VLIQTSSMGV IGGARCQYHL RQILVFLDAM VMNKPEFMGG
160 170 180
VIQNKVDPQT GEVIDQGTLD HLTGQLTAFG EFIQRVKI
Length:188
Mass (Da):20,376
Last modified:December 20, 2005 - v1
Checksum:i78E163CC4826905D
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
L10328 Genomic DNA. Translation: AAA62064.1.
U00096 Genomic DNA. Translation: AAC76736.1.
AP009048 Genomic DNA. Translation: BAE77575.1.
PIRiB65174.
RefSeqiNP_418169.1. NC_000913.3.
WP_001291268.1. NZ_LN832404.1.

Genome annotation databases

EnsemblBacteriaiAAC76736; AAC76736; b3713.
BAE77575; BAE77575; BAE77575.
GeneIDi948225.
KEGGiecj:JW3691.
eco:b3713.
PATRICifig|1411691.4.peg.2988.

Similar proteinsi

Entry informationi

Entry nameiCHRR_ECOLI
AccessioniPrimary (citable) accession number: P0AGE6
Secondary accession number(s): P31465, Q2M831
Entry historyiIntegrated into UniProtKB/Swiss-Prot: December 20, 2005
Last sequence update: December 20, 2005
Last modified: November 22, 2017
This is version 94 of the entry and version 1 of the sequence. See 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