Q97U27 · GAD_SACS2

Function

function

Involved in the degradation of glucose and galactose via the branched variant of the Entner-Doudoroff pathway. Catalyzes the dehydration of gluconate to produce 2-keto-3-deoxygluconate (KDG). It is also able to catalyze the dehydration of galactonate to produce 2-keto-3-deoxygalactonate (KDGal).

Miscellaneous

D-gluconate dehydratase activity is lost after incubation with phosphatase, whereas no such decrease in activity is observed when the enzymes are incubated in the same reaction mixtures without phosphatase. Analysis of the amino acid sequence of D-gluconate dehydratase indicate the presence of several putative phosphorylation sites on serine, threonine and tyrosine residues.

Catalytic activity

Cofactor

Mg2+ (UniProtKB | Rhea| CHEBI:18420 )

Co2+ (UniProtKB | Rhea| CHEBI:48828 )

Mn2+ (UniProtKB | Rhea| CHEBI:29035 )

Ni2+ (UniProtKB | Rhea| CHEBI:49786 )

Note: Binds 1 Mg2+ ion per subunit. Can also use divalent metal ions such as Co2+, Mn2+ and Ni2+.

Kinetics

KM SUBSTRATE pH TEMPERATURE[C] NOTES EVIDENCE
0.45 mMgluconate778
0.81 mMgalactonate670
1.57 mMgluconate670
Vmax pH TEMPERATURE[C] NOTES EVIDENCE
0.15 μmol/min/mg778with gluconate as substrate
kcat is 10.4 sec-1 for gluconate and 1.08 sec-1 for galactonate (at 70 degrees Celsius and pH 6). kcat is 12.6 sec-1 for gluconate (at 78 degrees Celsius and pH 7).

pH Dependence

Optimum pH is between 6.5 and 7.5.

Temperature Dependence

Optimum temperature is between 80 and 100 degrees Celsius. At 80 degrees Celsius, the dehydratase is stable for over 2 hours, but at 90 degrees Celsius its activity is decreased to less than 50% in 2 hours and its half-life diminishes to 120 minutes. At 100 degrees Celsius, the enzyme has a half-life of less than 40 minutes. The activity is almost undetectable below 60 degrees Celsius.

Pathway

Carbohydrate acid metabolism; D-gluconate degradation.

Features

Showing features for binding site, active site, site.

TypeIDPosition(s)Description
Binding site197Mg2+ (UniProtKB | ChEBI)
Active site199Proton donor
Binding site223Mg2+ (UniProtKB | ChEBI)
Binding site249Mg2+ (UniProtKB | ChEBI)
Site272Increases basicity of active site His
Active site299Proton acceptor
Site324Transition state stabilizer

GO annotations

AspectTerm
Molecular Functiongalactonate dehydratase activity
Molecular Functiongluconate dehydratase activity
Molecular Functionmetal ion binding
Biological ProcessD-gluconate catabolic process

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

Gene names

    • Name
      gad
    • Synonyms
      gnaD
    • Ordered locus names
      SSO3198

Organism names

Accessions

  • Primary accession
    Q97U27

Proteomes

PTM/Processing

Features

Showing features for chain.

TypeIDPosition(s)Description
ChainPRO_00004226501-395D-gluconate/D-galactonate dehydratase

Proteomic databases

Interaction

Subunit

Monomer or homooctamer.

Protein-protein interaction databases

Structure

Family & Domains

Sequence similarities

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    395
  • Mass (Da)
    44,729
  • Last updated
    2001-10-01 v1
  • Checksum
    BA53EFD93F90A44D
MRIREIEPIVLTSKEKGSATWASIMIVTRVITENGEVGYGEAVPTLRVISVYNAIKQVSKAYIGKEVEEVEKNYHEWYKQDFYLARSFESATAVSAIDIASWDIIGKELGAPIHKLLGGKTRDRVPVYANGWYQDCVTPEEFAEKAKDVVKMGYKALKFDPFGPYYDWIDERGLREAEERVKAVREAVGDNVDILIEHHGRFNANSAIMIAKRLEKYNPGFMEEPVHHEDVIGLRKYKASTHLRVALGERLISEKETAFYVEEGLVNILQPDLTNIGGVTVGRSVIKIAEANDVEVAFHNAFGSIQNAVEIQLSAVTQNLYLLENFYDWFPQWKRDLVYNETPVEGGHVKVPYKPGLGVSINEKIIEQLRAEPIPLDVIEEPVWVVKGTWKNYGV

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AE006641
EMBL· GenBank· DDBJ
AAK43295.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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