GapMind for Amino acid biosynthesis


L-arginine biosynthesis in Thioalkalivibrio thiocyanodenitrificans ARhD 1

Best path

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.

21 steps (16 with candidates)

Or see definitions of steps

Step Description Best candidate 2nd candidate
argA N-acylglutamate synthase THITHI_RS0108035 THITHI_RS0107045
argB N-acylglutamate kinase THITHI_RS0112025 THITHI_RS0108035
argC N-acylglutamylphosphate reductase THITHI_RS0106205
argD N-acetylornithine aminotransferase THITHI_RS0106505 THITHI_RS0106275
argE N-acetylornithine deacetylase THITHI_RS0108030
carA carbamoyl phosphate synthase subunit alpha THITHI_RS0115805
carB carbamoyl phosphate synthase subunit beta THITHI_RS0115810
argI ornithine carbamoyltransferase THITHI_RS0106510 THITHI_RS0108790
argG arginosuccinate synthetase THITHI_RS0106430
argH argininosuccinate lyase THITHI_RS0111195
Alternative steps:
argD'B N-succinylornithine aminotransferase THITHI_RS0106505 THITHI_RS0103415
argE'B N-succinylcitrulline desuccinylase
argF' acetylornithine transcarbamoylase THITHI_RS0106510
argF'B N-succinylornithine carbamoyltransferase
argJ ornithine acetyltransferase THITHI_RS0107045
argX glutamate--LysW ligase
lysJ [LysW]-glutamate-semialdehyde aminotransferase THITHI_RS0106505 THITHI_RS0106275
lysK [LysW]-ornithine hydrolase
lysW 2-aminoadipate/glutamate carrier protein
lysY [LysW]-glutamate-6-phosphate reductase THITHI_RS0106205
lysZ [LysW]-glutamate kinase THITHI_RS0112025

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