argA, argB, argC, argD, argE, carA, carB, argI, argG, argH
Overview: Arginine biosynthesis in GapMind is based on MetaCyc pathways L-arginine biosynthesis I via L-acetyl-ornithine (link), II (acetyl cycle) (link), III via N-acetyl-L-citrulline (link), or IV via LysW-ornithine (link). GapMind also includes L-arginine biosynthesis with succinylated intermediates, as in Bacteroidetes (PMC5764234). These pathways all involve the activation of glutamate (by aceylation, succinylation, or attachment of LysW), followed by phosphorylation, reduction and transamination, to activated ornithine. In most pathways, this intermediate is cleaved to ornithine before transcarbamoylation, but in the N-acetylcitrulline or succinylated pathways, transcarbamoylation occurs before hydrolysis. In the final two steps, citrulline is converted to arginine by ArgG and ArgH.
Or see definitions of steps
| Step | Description | Best candidate | 2nd candidate |
|---|---|---|---|
| argA | N-acylglutamate synthase | AZL_RS25275 | AZL_RS13670 |
| argB | N-acylglutamate kinase | AZL_RS25275 | AZL_RS02775 |
| argC | N-acylglutamylphosphate reductase | AZL_RS15610 | AZL_RS25275 |
| argD | N-acetylornithine aminotransferase | AZL_RS02205 | AZL_RS24705 |
| argE | N-acetylornithine deacetylase | AZL_RS26180 | AZL_RS31045 |
| carA | carbamoyl phosphate synthase subunit alpha | AZL_RS05565 | |
| carB | carbamoyl phosphate synthase subunit beta | AZL_RS01400 | |
| argI | ornithine carbamoyltransferase | AZL_RS02200 | AZL_RS08275 |
| argG | arginosuccinate synthetase | AZL_RS01130 | |
| argH | argininosuccinate lyase | AZL_RS27925 | |
| Alternative steps: | |||
| argD'B | N-succinylornithine aminotransferase | AZL_RS02205 | AZL_RS19185 |
| argE'B | N-succinylcitrulline desuccinylase | ||
| argF' | acetylornithine transcarbamoylase | AZL_RS02200 | |
| argF'B | N-succinylornithine carbamoyltransferase | ||
| argJ | ornithine acetyltransferase | AZL_RS13670 | |
| argX | glutamate--LysW ligase | ||
| lysJ | [LysW]-glutamate-semialdehyde aminotransferase | AZL_RS02205 | AZL_RS24705 |
| lysK | [LysW]-ornithine hydrolase | ||
| lysW | 2-aminoadipate/glutamate carrier protein | ||
| lysY | [LysW]-glutamate-6-phosphate reductase | AZL_RS15610 | |
| lysZ | [LysW]-glutamate kinase | AZL_RS02775 | |
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 Apr 10 2024. The underlying query database was built on Apr 09 2024.
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:
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:
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