GapMind for catabolism of small carbon sources


L-tryptophan catabolism in Desulfovibrio vulgaris Hildenborough

Best path

tnaB, tnaA


Overview: Tryptophan degradation in GapMind is based on MetaCyc degradation pathways I via anthranilate (link), II via pyruvate (link), or IX via 3-hydroxyanthranilate (link). Pathway XII (link) overlaps with pathway I and is also represented. The other MetaCyc pathways do not yield fixed carbon or are not reported in prokaryotes, and are not included. For example, pathway IV yields indole-3-lactate, which could potentially be oxidized to indole-3-acetate, which has a known catabolic pathway, but no prokaryotes are known to consume tryptophan this way. Pathway VIII yields tryptophol (also known as indole-3-ethanol), which could potentially be oxidized to indole-3-acetate and consumed. Pathways X and XIII yield indole-3-propionate, which may spontaneously oxidize to kynurate, but kynurate catabolism is not reported.

47 steps (13 with candidates)

Or see definitions of steps

Step Description Best candidate 2nd candidate
tnaB tryptophan:H+ symporter TnaB DVU2205 DVU3297
tnaA tryptophanase DVU2204
Alternative steps:
ackA acetate kinase DVU0723 DVU3030
acs acetyl-CoA synthetase, AMP-forming DVU2969 DVU0748
adh acetaldehyde dehydrogenase (not acylating) DVU3319 DVU3294
ald-dh-CoA acetaldehyde dehydrogenase, acylating
andAa anthranilate 1,2-dioxygenase (deaminating, decarboxylating), ferredoxin--NAD(+) reductase component AndAa
andAb anthranilate 1,2-dioxygenase (deaminating, decarboxylating), ferredoxin subunit AndAb
andAc anthranilate 1,2-dioxygenase (deaminating, decarboxylating), large subunit AndAc
andAd athranilate 1,2-dioxygenase (deaminating, decarboxylating), small subunit AndAd
antA anthranilate 1,2-dioxygenase (deaminating, decarboxylating), large subunit AntA
antB anthranilate 1,2-dioxygenase (deaminating, decarboxylating), small subunit AntB
antC anthranilate 1,2-dioxygenase (deaminating, decarboxylating), electron transfer component AntC
aroP tryptophan:H+ symporter AroP
catA catechol 1,2-dioxygenase
catB muconate cycloisomerase
catC muconolactone isomerase
catI 3-oxoadipate CoA-transferase subunit A (CatI)
catJ 3-oxoadipate CoA-transferase subunit B (CatJ)
ecfA1 energy-coupling factor transporter, ATPase 1 (A1) component DVU2299 DVU0098
ecfA2 energy-coupling factor transporter, ATPase 2 (A2) component DVU1236 DVU0388
ecfT energy-coupling factor transporter, transmembrane (T) component
hpaH anthranilate 3-monooxygenase (hydroxylase), FADH2-dependent
kyn kynureninase
kynA tryptophan 2,3-dioxygenase
kynB kynurenine formamidase
mhpD 2-hydroxypentadienoate hydratase
mhpE 4-hydroxy-2-oxovalerate aldolase DVU0343 DVUA0016
nbaC 3-hydroxyanthranilate 3,4-dioxygenase
nbaD 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase
nbaE 2-aminomuconate 6-semialdehyde dehydrogenase DVU3319
nbaF 2-aminomuconate deaminase DVU0808 DVU0620
nbaG 2-oxo-3-hexenedioate decarboxylase
pcaD 3-oxoadipate enol-lactone hydrolase
pcaF succinyl-CoA:acetyl-CoA C-succinyltransferase
pcaI 3-oxoadipate CoA-transferase subunit A (PcaI)
pcaJ 3-oxoadipate CoA-transferase subunit B (PcaJ)
praB 2-hydroxymuconate 6-semialdehyde dehydrogenase DVU3319
praC 2-hydroxymuconate tautomerase DVU2421
praD 2-oxohex-3-enedioate decarboxylase
pta phosphate acetyltransferase DVU3029 DVU0627
sibC L-kynurenine 3-monooxygenase
TAT tryptophan permease
tnaT tryptophan:Na+ symporter TnaT
trpP energy-coupling factor transporter, tryptophan-specific (S) component TrpP
xylE catechol 2,3-dioxygenase
xylF 2-hydroxymuconate semialdehyde hydrolase

Confidence: high confidence medium confidence low confidence
transporter – transporters and PTS systems are shaded because predicting their specificity is particularly challenging.

This GapMind analysis is from Sep 17 2021. The underlying query database was built on Sep 17 2021.



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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