chorismate biosynthesis in Novosphingobium aromaticivorans DSM 12444

GapMind for Amino acid biosynthesis

chorismate biosynthesis in Novosphingobium aromaticivorans DSM 12444

Best path

aroG, aroB, aroD, aroE, aroL, aroA, aroC

Rules

Overview: Chorismate is the starting point for the biosynthesis of the aromatic amino acids phenylalanine, tryptophan, and tyrosine. Chorismate biosynthesis in GapMind is based on MetaCyc pathways chorismate biosynthesis I (link), from D-erythrose-4-phosphate and phosphoenolpyruvate, or II (link), from D-glyceraldeyde-3-phosphate and L-asparatate. Both pathways are identical after they reach 3-dehydroquinate.

all: 3-dehydroquinate, aroD, aroE, aroL, aroA and aroC
3-dehydroquinate:

aroG and aroB
or tpiA, fbp, aspartate-semialdehyde, aroA' and aroB'
Comment: Pathway I uses aroG and aroB, while pathway II uses non-canonical activities of triose-phosphate isomerase (tpiA) and fructose-bisphosphate aldolase (fbp) to form 6-deoxy-5-ketofructose 1-phosphate. AroA' condenses this with asparate semialdehyde to 2-amino-3,7-dideoxy-D-threo-hept-6-ulosonate, and AroB' cyclizes it to 3-dehydroquinate.

aspartate-semialdehyde: asp-kinase and asd

13 steps (11 with candidates)

Or see definitions of steps

Step	Description	Best candidate	2nd candidate
aroG	3-deoxy-7-phosphoheptulonate synthase	SARO_RS04950	SARO_RS03630
aroB	3-dehydroquinate synthase	SARO_RS09510
aroD	3-dehydroquinate dehydratase	SARO_RS10450
aroE	shikimate dehydrogenase	SARO_RS07970	SARO_RS00575
aroL	shikimate kinase	SARO_RS09515	SARO_RS06355
aroA	3-phosphoshikimate 1-carboxyvinyltransferase	SARO_RS06630
aroC	chorismate synthase	SARO_RS00045
Alternative steps:
aroA'	2-amino-3,7-dideoxy-D-threo-hept-6-ulosonate synthase
aroB'	dehydroquinate synthase II
asd	aspartate semi-aldehyde dehydrogenase	SARO_RS07070
asp-kinase	aspartate kinase	SARO_RS16780
fbp	6-deoxy-5-ketofructose 1-phosphate synthase	SARO_RS09855
tpiA	D-glyceraldehyde-3-phosphate phospholyase	SARO_RS10155	SARO_RS09860

Confidence: high confidence medium confidence low confidence
? – known gap: despite the lack of a good candidate for this step, this organism (or a related organism) performs the pathway

This GapMind analysis is from Jul 25 2024. The underlying query database was built on Jul 25 2024.

Downloads

Candidates (tab-delimited)
Steps (tab-delimited)
Rules (tab-delimited)
Protein sequences (fasta format)
Organisms (tab-delimited)
SQLite3 databases

Related tools

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:

ublast finds a hit to a characterized protein at above 40% identity and 80% coverage, and bits >= other bits+10.
- (Hits to curated proteins without experimental data as to their function are never considered high confidence.)
HMMer finds a hit with 80% coverage of the model, and either other identity < 40 or other coverage < 0.75.

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:

ublast finds a hit at above 40% identity and 70% coverage (ignoring otherBits).
ublast finds a hit at above 30% identity and 80% coverage, and bits >= other bits.
HMMer finds a hit (regardless of coverage or other bits).

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:

our ignorance of proteins' functions,
omissions in the gene models,
frame-shift errors in the genome sequence, or
the organism lacks the pathway.

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 2024 update on GapMind for amino acid biosynthesis
the paper from 2022 on GapMind for carbon sources
the source code
instructions for running GapMind on your computer
changes to Amino acid biosynthesis since the original publication.

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

GapMind for Amino acid biosynthesis