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Protein

Ketol-acid reductoisomerase (NADP(+))

Gene

ilvC

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

Functioni

Involved in the biosynthesis of branched-chain amino acids (BCAA). Catalyzes an alkyl-migration followed by a ketol-acid reduction of (S)-2-acetolactate (S2AL) to yield (R)-2,3-dihydroxy-isovalerate. In the isomerase reaction, S2AL is rearranged via a Mg-dependent methyl migration to produce 3-hydroxy-3-methyl-2-ketobutyrate (HMKB). In the reductase reaction, this 2-ketoacid undergoes a metal-dependent reduction by NADPH to yield (R)-2,3-dihydroxy-isovalerate. Also able to use 2-ketopantoate, 2-ketoisovalerate, 2-ketovalerate, 2-ketobutyrate, 3-hydroxypyruvate, 3-hydroxy-2-ketobutyrate and pyruvate (PubMed:15654896).4 Publications

Catalytic activityi

(2R)-2,3-dihydroxy-3-methylbutanoate + NADP+ = (2S)-2-hydroxy-2-methyl-3-oxobutanoate + NADPH.UniRule annotation4 Publications
(2R,3R)-2,3-dihydroxy-3-methylpentanoate + NADP+ = (S)-2-hydroxy-2-ethyl-3-oxobutanoate + NADPH.UniRule annotation

Cofactori

Mg2+UniRule annotation3 PublicationsNote: Binds 2 magnesium ions per subunit.UniRule annotation2 Publications

Enzyme regulationi

Inhibited by N-hydroxy-N-isopropyloxamate (IpOHA).1 Publication

Kineticsi

Kcat is 7.2 min(-1) for reductoisomerase activity with NADPH as substrate (PubMed:9015391). Kcat is 3.1 min(-1) for reductoisomerase activity with NADPH as substrate (PubMed:9015391). Kcat is 0.11 min(-1) for reductoisomerase activity with NADH as substrate (PubMed:9015391). Kcat is 5.376 sec(-1) for reductoisomerase activity with 3-hydroxypyruvate as substrate (at pH 8 and 37 degrees Celsius) (PubMed:15654896). Kcat is 3.6 sec(-1) for reductoisomerase activity with NADPH as substrate (PubMed:21515217). Kcat is 3.511 sec(-1) for reductoisomerase activity with 3-hydroxy-3-methyl-2-ketobutyrate as substrate (at pH 8 and 37 degrees Celsius) (PubMed:15654896). Kcat is 2.231 sec(-1) for reductoisomerase activity with 2-acetolactate as substrate (at pH 8 and 37 degrees Celsius) (PubMed:15654896). Kcat is 0.594 sec(-1) for reductoisomerase activity with 3-hydroxy-2-ketobutyrate as substrate (at pH 8 and 37 degrees Celsius) (PubMed:15654896). Kcat is 0.3 sec(-1) for reductoisomerase activity with NADH as substrate (PubMed:21515217). Kcat is 0.194 sec(-1) for reductoisomerase activity with 2-ketopantoate as substrate (at pH 8 and 37 degrees Celsius) (PubMed:15654896). Kcat is 0.182 sec(-1) for reductoisomerase activity with 2-ketoisovalerate as substrate (at pH 8 and 37 degrees Celsius) (PubMed:15654896). Kcat is 0.167 sec(-1) for reductoisomerase activity with 2-ketobutyrate as substrate (at pH 8 and 37 degrees Celsius) (PubMed:15654896). Kcat is 0.05 sec(-1) for reductoisomerase activity with 2-ketovalerate as substrate (at pH 8 and 37 degrees Celsius) (PubMed:15654896). Kcat is 0.021 sec(-1) for reductoisomerase activity with pyruvate as substrate (at pH 8 and 37 degrees Celsius) (PubMed:15654896).3 Publications
  1. KM=0.04 mM for NADPH1 Publication
  2. KM=0.042 mM for NADP1 Publication
  3. KM=0.073 mM for NADPH1 Publication
  4. KM=0.17 mM for 2-ketopantoate (at pH 8 and 37 degrees Celsius)1 Publication
  5. KM=0.206 mM for NADH1 Publication
  6. KM=0.21 mM for 3-hydroxy-2-ketobutyrate (at pH 8 and 37 degrees Celsius)1 Publication
  7. KM=0.25 mM for 2-acetolactate (at pH 8 and 37 degrees Celsius)1 Publication
  8. KM=0.27 mM for 3-hydroxy-3-methyl-2-ketobutyrate (at pH 8 and 37 degrees Celsius)1 Publication
  9. KM=0.42 mM for magnesium (with S2AL and NADPH as substrates)1 Publication
  10. KM=1.08 mM for NADH1 Publication
  11. KM=1.54 mM for pyruvate (at pH 8 and 37 degrees Celsius)1 Publication
  12. KM=2.96 mM for 3-hydroxypyruvate (at pH 8 and 37 degrees Celsius)1 Publication
  13. KM=3.15 mM for 2-ketovalerate (at pH 8 and 37 degrees Celsius)1 Publication
  14. KM=4.56 mM for 2-ketobutyrate (at pH 8 and 37 degrees Celsius)1 Publication
  15. KM=6.91 mM for 2-ketoisovalerate (at pH 8 and 37 degrees Celsius)1 Publication
  1. Vmax=5.421 µmol/min/mg enzyme with 3-hydroxypyruvate as substrate (at pH 8 and 37 degrees Celsius)1 Publication
  2. Vmax=3.541 µmol/min/mg enzyme with 3-hydroxy-3-methyl-2-ketobutyrate as substrate (at pH 8 and 37 degrees Celsius)1 Publication
  3. Vmax=2.25 µmol/min/mg enzyme with 2-acetolactate as substrate (at pH 8 and 37 degrees Celsius)1 Publication
  4. Vmax=0.599 µmol/min/mg enzyme with 3-hydroxy-2-ketobutyrate as substrate (at pH 8 and 37 degrees Celsius)1 Publication
  5. Vmax=0.196 µmol/min/mg enzyme with 2-ketopantoate as substrate (at pH 8 and 37 degrees Celsius)1 Publication
  6. Vmax=0.184 µmol/min/mg enzyme with 2-ketoisovalerate as substrate (at pH 8 and 37 degrees Celsius)1 Publication
  7. Vmax=0.168 µmol/min/mg enzyme with 2-ketobutyrate as substrate (at pH 8 and 37 degrees Celsius)1 Publication
  8. Vmax=0.05 µmol/min/mg enzyme with 2-ketovalerate as substrate (at pH 8 and 37 degrees Celsius)1 Publication
  9. Vmax=0.021 µmol/min/mg enzyme with pyruvate as substrate (at pH 8 and 37 degrees Celsius)1 Publication

Pathwayi: L-isoleucine biosynthesis

This protein is involved in step 2 of the subpathway that synthesizes L-isoleucine from 2-oxobutanoate.UniRule annotation1 Publication
Proteins known to be involved in the 4 steps of the subpathway in this organism are:
  1. Acetolactate synthase isozyme 1 small subunit (ilvN), Putative acetolactate synthase isozyme 2 large subunit (ilvG), Acetolactate synthase isozyme 1 large subunit (ilvB), Acetolactate synthase isozyme 2 small subunit (ilvM), Acetolactate synthase isozyme 2 large subunit (ilvG), Acetolactate synthase isozyme 3 large subunit (ilvI), Acetolactate synthase isozyme 3 small subunit (ilvH)
  2. Ketol-acid reductoisomerase (NADP(+)) (ilvC)
  3. Dihydroxy-acid dehydratase (ilvD)
  4. Branched-chain-amino-acid aminotransferase (ilvE)
This subpathway is part of the pathway L-isoleucine biosynthesis, which is itself part of Amino-acid biosynthesis.
View all proteins of this organism that are known to be involved in the subpathway that synthesizes L-isoleucine from 2-oxobutanoate, the pathway L-isoleucine biosynthesis and in Amino-acid biosynthesis.

Pathwayi: L-valine biosynthesis

This protein is involved in step 2 of the subpathway that synthesizes L-valine from pyruvate.UniRule annotation1 Publication
Proteins known to be involved in the 4 steps of the subpathway in this organism are:
  1. Acetolactate synthase isozyme 1 small subunit (ilvN), Putative acetolactate synthase isozyme 2 large subunit (ilvG), Acetolactate synthase isozyme 1 large subunit (ilvB), Acetolactate synthase isozyme 2 small subunit (ilvM), Acetolactate synthase isozyme 2 large subunit (ilvG), Acetolactate synthase isozyme 3 large subunit (ilvI), Acetolactate synthase isozyme 3 small subunit (ilvH)
  2. Ketol-acid reductoisomerase (NADP(+)) (ilvC)
  3. Dihydroxy-acid dehydratase (ilvD)
  4. Branched-chain-amino-acid aminotransferase (ilvE)
This subpathway is part of the pathway L-valine biosynthesis, which is itself part of Amino-acid biosynthesis.
View all proteins of this organism that are known to be involved in the subpathway that synthesizes L-valine from pyruvate, the pathway L-valine biosynthesis and in Amino-acid biosynthesis.

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Binding sitei68NADPUniRule annotation1 Publication1
Binding sitei76NADPUniRule annotation1 Publication1 Publication1
Binding sitei78NADPUniRule annotation1 Publication1
Active sitei132UniRule annotation1
Binding sitei158NADP; via amide nitrogenUniRule annotation1
Metal bindingi217Magnesium 1UniRule annotation1 Publication1
Metal bindingi217Magnesium 2UniRule annotation1 Publication1
Metal bindingi221Magnesium 1UniRule annotation1
Metal bindingi389Magnesium 2UniRule annotation1 Publication1
Metal bindingi393Magnesium 2UniRule annotation1 Publication1
Binding sitei414SubstrateUniRule annotation1

Regions

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Nucleotide bindingi45 – 48NADPUniRule annotation1 Publication4
Nucleotide bindingi108 – 110NADPUniRule annotation1 Publication3

GO - Molecular functioni

  • identical protein binding Source: EcoCyc
  • ketol-acid reductoisomerase activity Source: UniProtKB
  • magnesium ion binding Source: UniProtKB
  • NADP binding Source: UniProtKB

GO - Biological processi

  • isoleucine biosynthetic process Source: EcoCyc
  • protein homotetramerization Source: EcoCyc
  • valine biosynthetic process Source: EcoCyc

Keywordsi

Molecular functionOxidoreductase
Biological processAmino-acid biosynthesis, Branched-chain amino acid biosynthesis
LigandMagnesium, Metal-binding, NADP

Enzyme and pathway databases

BioCyciEcoCyc:KETOLREDUCTOISOM-MONOMER
MetaCyc:KETOLREDUCTOISOM-MONOMER
BRENDAi1.1.1.86 2026
UniPathwayiUPA00047; UER00056
UPA00049; UER00060

Names & Taxonomyi

Protein namesi
Recommended name:
Ketol-acid reductoisomerase (NADP(+))1 PublicationUniRule annotation (EC:1.1.1.86UniRule annotation4 Publications)
Short name:
KARI1 PublicationUniRule annotation
Alternative name(s):
Acetohydroxy-acid isomeroreductase1 PublicationUniRule annotation
Short name:
AHIR1 PublicationUniRule annotation
Alpha-keto-beta-hydroxylacyl reductoisomeraseUniRule annotation
Ketol-acid reductoisomerase type 21 PublicationUniRule annotation
Ketol-acid reductoisomerase type II1 PublicationUniRule annotation
Gene namesi
Name:ilvCUniRule annotation
Ordered Locus Names:b3774, JW3747
OrganismiEscherichia coli (strain K12)
Taxonomic identifieri83333 [NCBI]
Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacteralesEnterobacteriaceaeEscherichia
Proteomesi
  • UP000000318 Componenti: Chromosome
  • UP000000625 Componenti: Chromosome

Organism-specific databases

EcoGeneiEG10495 ilvC

Subcellular locationi

  • Cytoplasm 1 Publication

GO - Cellular componenti

  • cytosol Source: EcoCyc

Keywords - Cellular componenti

Cytoplasm

Pathology & Biotechi

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi68R → D: Inversion of cofactor specificity from NADPH to NADH; when associated with L-69, V-75 and D-76. 1 Publication1
Mutagenesisi68R → Q: 18-fold decrease of the catalytic efficiency and 3-fold decrease of the affinity for NADPH. 1 Publication1
Mutagenesisi69K → L: Does not significantly alter the affinity for NADPH. Slight increase of the catalytic efficiency. Inversion of cofactor specificity from NADPH to NADH; when associated with D-68, V-75 and D-76. 1 Publication1
Mutagenesisi71A → S: 7- and 2.5-fold increase of the reductoisomerase activity with NADH and NADPH, respectively. 1 Publication1
Mutagenesisi75K → Q: 13-fold decrease of the catalytic efficiency and 3-fold increase of the affinity for NADPH. 1 Publication1
Mutagenesisi75K → V: Inversion of cofactor specificity from NADPH to NADH; when associated with D-68, L-69 and D-76. 1 Publication1
Mutagenesisi76R → D: 3-fold increase of the reductoisomerase activity with NADH and slight decrease of the reductoisomerase activity with NADPH. 1 Publication1
Mutagenesisi76R → D: Strong increase of catalytic efficiency and 2.5-fold increase of the affinity for NADH. 4-fold decrease of the catalytic efficiency and strong decrease of the affinity for NADPH. Inversion of cofactor specificity from NADPH to NADH; when associated with D-68, L-69 and V-75. 1 Publication1
Mutagenesisi76R → Q: 20-fold decrease of the catalytic efficiency and 5-fold decrease of the affinity for NADPH. 1 Publication1
Mutagenesisi78S → D: 12-fold increase of the reductoisomerase activity with NADH and slight decrease of the reductoisomerase activity with NADPH. 1 Publication1
Mutagenesisi110Q → V or A: 12- and 2-fold increase of the reductoisomerase activity with NADH and NADPH, respectively. 1 Publication1
Mutagenesisi132H → K: Loss of reductoisomerase activity. 1 Publication1
Mutagenesisi132H → Q: Loss of reductoisomerase activity. The reductase activity with 3-hydroxypyruvate and HMKB is nearly normal, and the isomerase activity decreases 24-fold. 1 Publication1
Mutagenesisi155K → E or Q: Loss of reductoisomerase activity. 1 Publication1
Mutagenesisi155K → R: Loss of reductoisomerase activity. The reductase activity with 3-hydroxypyruvate and HMKB is nearly normal, and the isomerase activity decreases 40-fold. 1 Publication1
Mutagenesisi213E → D: Loss of reductoisomerase activity. 1.5-fold decrease of the reductase activity with 3-hydroxypyruvate and the isomerase activity decreases 48-fold. 1 Publication1
Mutagenesisi217D → E or N: Loss of reductoisomerase activity. 1 Publication1
Mutagenesisi221E → D or Q: Loss of reductoisomerase activity. 1 Publication1
Mutagenesisi389E → D: Loss of reductoisomerase activity. 1.5-fold decrease of the reductase activity with 3-hydroxypyruvate and the isomerase activity decreases 4-fold. 1 Publication1
Mutagenesisi389E → Q: Loss of reductoisomerase activity. 1 Publication1
Mutagenesisi393E → D: Loss of reductoisomerase activity. The reductase activity with HMKB is nearly normal. 1 Publication1
Mutagenesisi414S → A: Loss of reductoisomerase activity. The isomerase activity decreases 15-fold. 1 Publication1
Mutagenesisi414S → T: Loss of reductoisomerase activity. The isomerase activity decreases 24-fold. 1 Publication1

Chemistry databases

ChEMBLiCHEMBL2366462

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Initiator methionineiRemoved1 Publication
ChainiPRO_00001513092 – 491Ketol-acid reductoisomerase (NADP(+))Add BLAST490

Proteomic databases

EPDiP05793
PaxDbiP05793
PRIDEiP05793

2D gel databases

SWISS-2DPAGEiP05793

Expressioni

Inductioni

In the presence of acetohydroxybutyrate and acetolactate and by the activator IlvY.2 Publications

Interactioni

Subunit structurei

Homotetramer.2 Publications

GO - Molecular functioni

  • identical protein binding Source: EcoCyc

Protein-protein interaction databases

BioGridi4263331, 21 interactors
IntActiP05793, 4 interactors
STRINGi316385.ECDH10B_3963

Chemistry databases

BindingDBiP05793

Structurei

Secondary structure

1491
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Helixi5 – 7Combined sources3
Helixi10 – 17Combined sources8
Beta strandi20 – 22Combined sources3
Helixi25 – 28Combined sources4
Turni29 – 32Combined sources4
Helixi33 – 35Combined sources3
Beta strandi38 – 44Combined sources7
Helixi47 – 58Combined sources12
Beta strandi62 – 67Combined sources6
Helixi69 – 73Combined sources5
Helixi77 – 84Combined sources8
Beta strandi88 – 91Combined sources4
Helixi92 – 95Combined sources4
Helixi96 – 98Combined sources3
Beta strandi100 – 104Combined sources5
Helixi108 – 110Combined sources3
Helixi111 – 118Combined sources8
Helixi119 – 121Combined sources3
Beta strandi127 – 132Combined sources6
Helixi134 – 137Combined sources4
Beta strandi147 – 156Combined sources10
Helixi158 – 166Combined sources9
Beta strandi173 – 177Combined sources5
Helixi179 – 181Combined sources3
Helixi187 – 197Combined sources11
Helixi200 – 202Combined sources3
Beta strandi205 – 207Combined sources3
Helixi210 – 222Combined sources13
Turni223 – 226Combined sources4
Helixi227 – 242Combined sources16
Helixi247 – 275Combined sources29
Helixi279 – 309Combined sources31
Helixi311 – 321Combined sources11
Turni322 – 324Combined sources3
Helixi325 – 336Combined sources12
Helixi338 – 341Combined sources4
Helixi351 – 356Combined sources6
Helixi359 – 377Combined sources19
Turni378 – 380Combined sources3
Helixi383 – 388Combined sources6
Helixi391 – 393Combined sources3
Helixi394 – 412Combined sources19
Helixi415 – 431Combined sources17
Helixi433 – 437Combined sources5
Beta strandi443 – 446Combined sources4
Helixi455 – 466Combined sources12
Helixi469 – 487Combined sources19

3D structure databases

ProteinModelPortaliP05793
SMRiP05793
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP05793

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini15 – 208KARI N-terminal RossmannPROSITE-ProRule annotation1 PublicationAdd BLAST194
Domaini209 – 344KARI C-terminal knotted 1PROSITE-ProRule annotation1 PublicationAdd BLAST136
Domaini345 – 484KARI C-terminal knotted 2PROSITE-ProRule annotation1 PublicationAdd BLAST140

Sequence similaritiesi

Belongs to the ketol-acid reductoisomerase family.UniRule annotation

Keywords - Domaini

Repeat

Phylogenomic databases

eggNOGiENOG4105C6M Bacteria
COG0059 LUCA
HOGENOMiHOG000286135
InParanoidiP05793
KOiK00053
OMAiKLFEMNR
PhylomeDBiP05793

Family and domain databases

Gene3Di1.10.1040.10, 1 hit
HAMAPiMF_00435 IlvC, 1 hit
InterProiView protein in InterPro
IPR008927 6-PGluconate_DH-like_C_sf
IPR013328 6PGD_dom2
IPR013023 KARI
IPR000506 KARI_C
IPR013116 KARI_N
IPR036291 NAD(P)-bd_dom_sf
PANTHERiPTHR21371 PTHR21371, 2 hits
PfamiView protein in Pfam
PF01450 IlvC, 2 hits
PF07991 IlvN, 1 hit
SUPFAMiSSF48179 SSF48179, 2 hits
SSF51735 SSF51735, 1 hit
TIGRFAMsiTIGR00465 ilvC, 1 hit
PROSITEiView protein in PROSITE
PS51851 KARI_C, 2 hits
PS51850 KARI_N, 1 hit

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P05793-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MANYFNTLNL RQQLAQLGKC RFMGRDEFAD GASYLQGKKV VIVGCGAQGL
60 70 80 90 100
NQGLNMRDSG LDISYALRKE AIAEKRASWR KATENGFKVG TYEELIPQAD
110 120 130 140 150
LVINLTPDKQ HSDVVRTVQP LMKDGAALGY SHGFNIVEVG EQIRKDITVV
160 170 180 190 200
MVAPKCPGTE VREEYKRGFG VPTLIAVHPE NDPKGEGMAI AKAWAAATGG
210 220 230 240 250
HRAGVLESSF VAEVKSDLMG EQTILCGMLQ AGSLLCFDKL VEEGTDPAYA
260 270 280 290 300
EKLIQFGWET ITEALKQGGI TLMMDRLSNP AKLRAYALSE QLKEIMAPLF
310 320 330 340 350
QKHMDDIISG EFSSGMMADW ANDDKKLLTW REETGKTAFE TAPQYEGKIG
360 370 380 390 400
EQEYFDKGVL MIAMVKAGVE LAFETMVDSG IIEESAYYES LHELPLIANT
410 420 430 440 450
IARKRLYEMN VVISDTAEYG NYLFSYACVP LLKPFMAELQ PGDLGKAIPE
460 470 480 490
GAVDNGQLRD VNEAIRSHAI EQVGKKLRGY MTDMKRIAVA G
Length:491
Mass (Da):54,069
Last modified:January 23, 2007 - v4
Checksum:i9CA34BA61C9AEBBA
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti251E → K in AAA24029 (PubMed:3003115).Curated1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M11689 Genomic DNA Translation: AAA24029.1
M87049 Genomic DNA Translation: AAA67577.1
U00096 Genomic DNA Translation: AAC76779.1
AP009048 Genomic DNA Translation: BAE77523.1
PIRiA65181 ISECKR
RefSeqiNP_418222.1, NC_000913.3
WP_000024939.1, NZ_LN832404.1

Genome annotation databases

EnsemblBacteriaiAAC76779; AAC76779; b3774
BAE77523; BAE77523; BAE77523
GeneIDi948286
KEGGiecj:JW3747
eco:b3774
PATRICifig|511145.12.peg.3891

Similar proteinsi

Entry informationi

Entry nameiILVC_ECOLI
AccessioniPrimary (citable) accession number: P05793
Secondary accession number(s): Q2M883
Entry historyiIntegrated into UniProtKB/Swiss-Prot: November 1, 1988
Last sequence update: January 23, 2007
Last modified: July 18, 2018
This is version 168 of the entry and version 4 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Direct protein sequencing, Reference proteome

Documents

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

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