GapMind for catabolism of small carbon sources


Definition of D-gluconate catabolism

As rules and steps, or see full text


Overview: In most bacteria, gluconate degradation proceeds via D-gluconate 6-phosphate and either the Entner-Doudoroff pathway or the oxidative pentose phosphate pathway (link). Alternatively, gluconate can be oxidized in the periplasm to 2-ketogluconate before uptake (link).


gntA: gluconate TRAP transporter, small permease component

gntB: gluconate TRAP transporter, large permease component

gntC: gluconate TRAP transporter, periplasmic solute-binding component

gntEIIA: gluconate PTS system, IIA component

gntEIIB: gluconate PTS system, IIB component

gntEIIC: gluconate PTS system, IIC component

gntEIID: gluconate PTS system, IID component

gntT: gluconate:H+ symporter GntT

ght3: gluconate transporter Ght3

gntK: D-gluconate kinase

gnd: 6-phosphogluconate dehydrogenase, decarboxylating

edd: phosphogluconate dehydratase

eda: 2-keto-3-deoxygluconate 6-phosphate aldolase

gadh1: gluconate 2-dehydrogenase flavoprotein subunit

gadh2: gluconate 2-dehydrogenase cytochrome c subunit

gadh3: gluconate 2-dehydrogenase subunit 3

kguT: 2-ketogluconate transporter

kguK: 2-ketogluconokinase

kguD: 2-keto-6-phosphogluconate reductase



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About GapMind

Each pathway is defined by a set of rules based on individual steps or genes. Candidates for each step are identified by using ublast (a fast alternative to protein BLAST) against a database of manually-curated proteins (most of which are experimentally characterized) or by using HMMer with enzyme models (usually from TIGRFam). Ublast hits may be split across two different proteins.

A candidate for a step is "high confidence" if either:

where "other" refers to the best ublast hit to a sequence that is not annotated as performing this step (and is not "ignored").

Otherwise, a candidate is "medium confidence" if either:

Other blast hits with at least 50% coverage are "low confidence."

Steps with no high- or medium-confidence candidates may be considered "gaps." For the typical bacterium that can make all 20 amino acids, there are 1-2 gaps in amino acid biosynthesis pathways. For diverse bacteria and archaea that can utilize a carbon source, there is a complete high-confidence catabolic pathway (including a transporter) just 38% of the time, and there is a complete medium-confidence pathway 63% of the time. Gaps may be due to:

GapMind relies on the predicted proteins in the genome and does not search the six-frame translation. In most cases, you can search the six-frame translation by clicking on links to Curated BLAST for each step definition (in the per-step page).

For more information, see the paper from 2019 on GapMind for amino acid biosynthesis, the paper from 2022 on GapMind for carbon sources, or view the source code.

If you notice any errors or omissions in the step descriptions, or any questionable results, please let us know

by Morgan Price, Arkin group, Lawrence Berkeley National Laboratory