GapMind for Amino acid biosynthesis


L-arginine biosynthesis in Methanosarcina acetivorans C2A

Best path

argJ, argB, argC, argD, 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
argJ ornithine acetyltransferase MA_RS18610
argB N-acylglutamate kinase MA_RS23550
argC N-acylglutamylphosphate reductase MA_RS18620
argD N-acetylornithine aminotransferase MA_RS00620 MA_RS15010
carA carbamoyl phosphate synthase subunit alpha MA_RS11135
carB carbamoyl phosphate synthase subunit beta MA_RS11130
argI ornithine carbamoyltransferase MA_RS17290 MA_RS23485
argG arginosuccinate synthetase MA_RS11125
argH argininosuccinate lyase MA_RS06830
Alternative steps:
argA N-acylglutamate synthase MA_RS18610 MA_RS22670
argD'B N-succinylornithine aminotransferase MA_RS00620 MA_RS15010
argE N-acetylornithine deacetylase MA_RS06200
argE'B N-succinylcitrulline desuccinylase
argF' acetylornithine transcarbamoylase MA_RS17290
argF'B N-succinylornithine carbamoyltransferase MA_RS17290
argX glutamate--LysW ligase MA_RS17050
lysJ [LysW]-glutamate-semialdehyde aminotransferase MA_RS00620 MA_RS15010
lysK [LysW]-ornithine hydrolase
lysW 2-aminoadipate/glutamate carrier protein
lysY [LysW]-glutamate-6-phosphate reductase MA_RS18620
lysZ [LysW]-glutamate kinase MA_RS23550

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