GapMind for Amino acid biosynthesis


L-arginine biosynthesis in Haloferax volcanii DS2

Best path

lysW, argX, lysZ, lysY, lysJ, lysK, 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.

21 steps (18 with candidates)

Or see definitions of steps

Step Description Best candidate 2nd candidate
lysW 2-aminoadipate/glutamate carrier protein C498_RS17895
argX glutamate--LysW ligase C498_RS17890
lysZ [LysW]-glutamate kinase C498_RS17880
lysY [LysW]-glutamate-6-phosphate reductase C498_RS17885
lysJ [LysW]-glutamate-semialdehyde aminotransferase C498_RS17875 C498_RS02300
lysK [LysW]-ornithine hydrolase C498_RS12835 C498_RS17870
carA carbamoyl phosphate synthase subunit alpha C498_RS07580
carB carbamoyl phosphate synthase subunit beta C498_RS06845
argI ornithine carbamoyltransferase C498_RS17865 C498_RS11065
argG arginosuccinate synthetase C498_RS17905
argH argininosuccinate lyase C498_RS17900
Alternative steps:
argA N-acylglutamate synthase C498_RS17040
argB N-acylglutamate kinase C498_RS17880
argC N-acylglutamylphosphate reductase C498_RS17885
argD N-acetylornithine aminotransferase C498_RS17875 C498_RS01375
argD'B N-succinylornithine aminotransferase C498_RS17875 C498_RS01375
argE N-acetylornithine deacetylase
argE'B N-succinylcitrulline desuccinylase
argF' acetylornithine transcarbamoylase C498_RS17865
argF'B N-succinylornithine carbamoyltransferase C498_RS17865
argJ ornithine acetyltransferase

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 09 2024. The underlying query database was built on Apr 09 2024.



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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:

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