Reaction: (1) D-gluconate = 2-dehydro-3-deoxy-D-gluconate + H2O
(2) D-galactonate = 2-dehydro-3-deoxy-D-galactonate + H2O
For diagram of reaction click here.
Other name(s): gluconate dehydratase (ambiguous); Sso3198 (gene name); Pto0485 (gene name)
Systematic name: D-gluconate/D-galactonate hydro-lyase
Comments: The enzyme is involved in glucose and galactose catabolism via the nonphosphorylative variant of the Entner-Doudoroff pathway in Picrophilus torridus [3] and via the branched variant of the Entner-Doudoroff pathway in Sulfolobus solfataricus [1,2]. In vitro it utilizes D-gluconate with 6-10 fold higher catalytic efficiency than D-galactonate [1,3]. It requires Mg2+ for activity [1,2]. cf. EC 4.2.1.6, galactonate dehydratase, and EC 4.2.1.39, gluconate dehydratase.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Lamble, H.J., Milburn, C.C., Taylor, G.L., Hough, D.W. and Danson, M.J. Gluconate dehydratase from the promiscuous Entner-Doudoroff pathway in Sulfolobus solfataricus. FEBS Lett 576 (2004) 133-136. [PMID: 15474024]
2. Ahmed, H., Ettema, T.J., Tjaden, B., Geerling, A.C., van der Oost, J. and Siebers, B. The semi-phosphorylative Entner-Doudoroff pathway in hyperthermophilic archaea: a re-evaluation. Biochem. J. 390 (2005) 529-540. [PMID: 15869466]
3. Reher, M., Fuhrer, T., Bott, M. and Schonheit, P. The nonphosphorylative Entner-Doudoroff pathway in the thermoacidophilic euryarchaeon Picrophilus torridus involves a novel 2-keto-3-deoxygluconate- specific aldolase. J. Bacteriol. 192 (2010) 964-974. [PMID: 20023024]