P50053 · KHK_HUMAN
- ProteinKetohexokinase
- GeneKHK
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids298 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Catalyzes the phosphorylation of the ketose sugar fructose to fructose-1-phosphate.
Catalytic activity
- ATP + beta-D-fructose = ADP + beta-D-fructose 1-phosphate + H+
Activity regulation
Requires potassium. Inhibition by ADP.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
0.8 mM | D-fructose | 25 | ||||
0.15 mM | Mg-ATP | 25 |
kcat is 7.6 sec-1.
Pathway
Carbohydrate metabolism; fructose metabolism.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 15 | beta-D-fructose (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 41 | beta-D-fructose (UniProtKB | ChEBI) | ||||
Sequence: G | ||||||
Binding site | 42 | beta-D-fructose (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Binding site | 45 | beta-D-fructose (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Binding site | 108 | ATP (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 226-229 | ATP (UniProtKB | ChEBI) | ||||
Sequence: AEEG | ||||||
Binding site | 255-258 | ATP (UniProtKB | ChEBI) | ||||
Sequence: GAGD | ||||||
Binding site | 258 | beta-D-fructose (UniProtKB | ChEBI) | ||||
Sequence: D |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Cellular Component | cytosol | |
Cellular Component | extracellular exosome | |
Molecular Function | ATP binding | |
Molecular Function | ketohexokinase activity | |
Biological Process | fructose metabolic process | |
Biological Process | regulation of glycogen metabolic process | |
Biological Process | response to fructose | |
Biological Process | response to glucose | |
Biological Process | response to insulin | |
Biological Process | response to sucrose | |
Biological Process | response to zinc ion |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameKetohexokinase
- EC number
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionP50053
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Disease & Variants
Involvement in disease
Fructosuria (FRUCT)
- Note
- DescriptionBenign defect of intermediary metabolism.
- See alsoMIM:229800
Natural variants in FRUCT
Variant ID | Position(s) | Change | Description | |
---|---|---|---|---|
VAR_006072 | 40 | G>R | in FRUCT; loss of ketohexokinase function; insoluble; dbSNP:rs104893643 | |
VAR_006073 | 43 | A>T | in FRUCT; no effect on ketohexokinase function; decreases enzyme activity but no effect in substrate affinity; decreases thermal stability; dbSNP:rs104893644 |
Features
Showing features for natural variant.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Natural variant | VAR_006072 | 40 | in FRUCT; loss of ketohexokinase function; insoluble; dbSNP:rs104893643 | |||
Sequence: G → R | ||||||
Natural variant | VAR_006073 | 43 | in FRUCT; no effect on ketohexokinase function; decreases enzyme activity but no effect in substrate affinity; decreases thermal stability; dbSNP:rs104893644 | |||
Sequence: A → T | ||||||
Natural variant | VAR_006074 | 49 | in dbSNP:rs2304681 | |||
Sequence: V → I |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 386 variants from UniProt as well as other sources including ClinVar and dbSNP.
Keywords
- Disease
Organism-specific databases
Miscellaneous
Chemistry
Genetic variation databases
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000080088 | 1-298 | Ketohexokinase | |||
Sequence: MEEKQILCVGLVVLDVISLVDKYPKEDSEIRCLSQRWQRGGNASNSCTVLSLLGAPCAFMGSMAPGHVADFLVADFRRRGVDVSQVAWQSKGDTPSSCCIINNSNGNRTIVLHDTSLPDVSATDFEKVDLTQFKWIHIEGRNASEQVKMLQRIDAHNTRQPPEQKIRVSVEVEKPREELFQLFGYGDVVFVSKDVAKHLGFQSAEEALRGLYGRVRKGAVLVCAWAEEGADALGPDGKLLHSDAFPPPRVVDTLGAGDTFNASVIFSLSQGRSVQEALRFGCQVAGKKCGLQGFDGIV |
Proteomic databases
2D gel databases
PTM databases
Expression
Tissue specificity
Most abundant in liver, kidney, gut, spleen and pancreas. Low levels also found in adrenal, muscle, brain and eye.
Gene expression databases
Organism-specific databases
Interaction
Subunit
Homodimer.
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
BINARY | P50053 | LHX9 Q9NQ69 | 3 | EBI-1053974, EBI-10175218 | |
BINARY | P50053-2 | APPBP2 Q92624 | 3 | EBI-12204387, EBI-743771 | |
BINARY | P50053-2 | LHX2 P50458 | 3 | EBI-12204387, EBI-12179869 | |
BINARY | P50053-2 | LHX9 Q9NQ69 | 3 | EBI-12204387, EBI-10175218 | |
BINARY | P50053-2 | PRPS1 P60891-1 | 4 | EBI-12204387, EBI-16205225 |
Protein-protein interaction databases
Chemistry
Miscellaneous
Structure
Sequence & Isoform
- Sequence statusComplete
This entry describes 2 isoforms produced by Alternative splicing.
P50053-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- NameC
- SynonymsCentral, hepatic/renal/intestinal
- Length298
- Mass (Da)32,523
- Last updated2015-04-29 v2
- ChecksumBE77FC325CAC5721
P50053-2
- NameA
- SynonymsPeripheral
- NoteMore widely distributed but with a low expression level. KM=7 mM for D-fructose (at 25 degrees Celsius). KM=036 mM for Mg-ATP (at 25 degrees Celsius). kcat is 6.9 sec-1.
- Differences from canonical
- 72-115: LVADFRRRGVDVSQVAWQSKGDTPSSCCIINNSNGNRTIVLHDT → VLDDLRRYSVDLRYTVFQTTGSVPIATVIINEASGSRTILYYDR
Computationally mapped potential isoform sequences
There is 1 potential isoform mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
C9JDL1 | C9JDL1_HUMAN | KHK | 343 |
Features
Showing features for alternative sequence.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Alternative sequence | VSP_004669 | 72-115 | in isoform A | |||
Sequence: LVADFRRRGVDVSQVAWQSKGDTPSSCCIINNSNGNRTIVLHDT → VLDDLRRYSVDLRYTVFQTTGSVPIATVIINEASGSRTILYYDR |
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
X78678 EMBL· GenBank· DDBJ | CAA55347.1 EMBL· GenBank· DDBJ | mRNA | ||
X78677 EMBL· GenBank· DDBJ | CAA55346.1 EMBL· GenBank· DDBJ | mRNA | ||
CR456801 EMBL· GenBank· DDBJ | CAG33082.1 EMBL· GenBank· DDBJ | mRNA | ||
AC013403 EMBL· GenBank· DDBJ | AAX93167.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CH471053 EMBL· GenBank· DDBJ | EAX00643.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
BC006233 EMBL· GenBank· DDBJ | AAH06233.1 EMBL· GenBank· DDBJ | mRNA | ||
Y09336 EMBL· GenBank· DDBJ | CAA70516.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
Y09341 EMBL· GenBank· DDBJ | CAA70522.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
Y09341 EMBL· GenBank· DDBJ | CAA70523.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
Y09340 EMBL· GenBank· DDBJ | CAA70521.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AJ005168 EMBL· GenBank· DDBJ | CAA06409.1 EMBL· GenBank· DDBJ | Genomic DNA |