Q58673 · LEUD_METJA
- ProteinIsopropylmalate/citramalate isomerase small subunit
- GeneleuD
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids168 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Enzyme with broad specificity that catalyzes reversible hydroxyacid isomerizations via dehydration/hydration reactions. Catalyzes the isomerization between 2-isopropylmalate and 3-isopropylmalate, via the formation of 2-isopropylmaleate, a step involved in leucine biosynthesis. Catalyzes the isomerization between 2-methylmalate and 3-methylmalate, via the formation of 2-methylmaleate (citraconate), a step involved in isoleucine biosynthesis. Also displays malease activity, i.e. catalyzes the hydration of maleate to form (R)-malate.
Catalytic activity
- (2R,3S)-3-isopropylmalate = (2S)-2-isopropylmalate
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
80 μM | 2-methylmaleate | |||||
810 μM | (R)-2-methylmalate | |||||
1900 μM | racemic 2-isopropylmalate | |||||
39 μM | racemic 3-isopropylmalate | |||||
400 μM | maleate |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
15 μmol/min/mg | for 2-methylmaleate hydration reaction | ||||
1.5 μmol/min/mg | for (R)-2-methylmalate dehydration reaction | ||||
4.2 μmol/min/mg | for 2-isopropylmalate dehydration reaction | ||||
1.8 μmol/min/mg | for 3-isopropylmalate dehydration reaction | ||||
34 μmol/min/mg | for maleate hydration reaction |
pH Dependence
Optimum pH is 7.5.
Temperature Dependence
Optimum temperature is 70 degrees Celsius.
Pathway
Amino-acid biosynthesis; L-leucine biosynthesis; L-leucine from 3-methyl-2-oxobutanoate: step 2/4.
Amino-acid biosynthesis; L-isoleucine biosynthesis; 2-oxobutanoate from pyruvate: step 2/3.
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | (R)-2-methylmalate dehydratase activity | |
Molecular Function | 3-isopropylmalate dehydratase activity | |
Molecular Function | maleate hydratase activity | |
Biological Process | isoleucine biosynthetic process | |
Biological Process | L-leucine biosynthetic process |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameIsopropylmalate/citramalate isomerase small subunit
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageArchaea > Euryarchaeota > Methanomada group > Methanococci > Methanococcales > Methanocaldococcaceae > Methanocaldococcus
Accessions
- Primary accessionQ58673
Proteomes
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000141937 | 1-168 | Isopropylmalate/citramalate isomerase small subunit | |||
Sequence: MRSIIKGRVWKFGNNVDTDAILPARYLVYTKPEELAQFVMTGADPDFPKKVKPGDIIVGGKNFGCGSSREHAPLGLKGAGISCVIAESFARIFYRNAINVGLPLIECKGISEKVNEGDELEVNLETGEIKNLTTGEVLKGQKLPEFMMEILEAGGLMPYLKKKMAESQ |
Proteomic databases
Interaction
Subunit
Heterotetramer of 2 LeuC and 2 LeuD. The heterotetramer that can be formed in vitro between HacA and LeuD is inactive.
Protein-protein interaction databases
Structure
Sequence
- Sequence statusComplete
- Length168
- Mass (Da)18,377
- Last updated1996-11-01 v1
- ChecksumA53C2CA883B6CCD7
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
L77117 EMBL· GenBank· DDBJ | AAB99283.1 EMBL· GenBank· DDBJ | Genomic DNA |