D-Galactonate is catabolized to give pyruvate and glyceraldehyde-3-phosphate by a pathway that involves the sequential reactions of galactonate dehydratase (GalD), 2-keto-3-deoxy-galactonate kinase (DgoK), and 6-phospho-2-keto-3-deoxy-galactonate aldolase (DgoA).
Only GalD was characterized experimentally.
Uptake of D-galactonate is believed to be mediated by DgoT in E.coli.

Open problems:
In E.coli, D-galactonate is taken up using specific permease. However in other species, it could be produced from D-galactose by galactose-1-dehydrogenase (EC 1.1.1.48) and in some organisms may require also 1,4-lactonase. In a-proteobacteria, DgoK and DgoA are present but homologous GalD is absent. In clusters with dgoK-dgoA there are numerouse genes that could supplement this gap:
1. putative dehydratase from the IlvD/Edd family;
2. Short chain dehydrogenase/reductase (similar to 3-oxoacyl-(acyl carrier protein) reductase)
3. galactose-1-dehydrogenase (EC 1.1.1.48)(pointing out for using D-galactose as a source)
4. Gluconolactonase (EC 3.1.1.17)
5. transcriptional regulator from the IclR family (predicted regulator of dgo genes)


References:
Science. 1995 Feb 24;267(5201):1159-61. PMID: 7855594
Szumilo T. J Bacteriol. 1981 Oct;148(1):368-70 (PMID: 7287628)