GapMind for Amino acid biosynthesis


L-proline biosynthesis in Halorhodospira halophila SL1

Best path

proB, proA, proC


Overview: Proline biosynthesis in GapMind is based on MetaCyc pathways L-proline biosynthesis I from L-glutamate (link) and III via L-ornithine aminotransferase (link). GapMind also describes proline synthesis via ornithine cyclodeaminase (PMID:11489875). Pathway II from arginine (link) should perhaps be included, but is not; it is reported in nitrogen-fixing cyanobacteria and the bacteria it was reported in also have pathway I. Pathway IV is not included because it is not reported in prokaryotes (link). Also, pathway III is described in MetaCyc as occuring only in plants, but it has been reported in the archaeon Thermococcus kodakarensis (PMC5846162).

17 steps (14 with candidates)

Or see definitions of steps

Step Description Best candidate 2nd candidate
proB glutamate 5-kinase HHAL_RS09315 HHAL_RS10820
proA gamma-glutamylphosphate reductase HHAL_RS10820 HHAL_RS09315
proC pyrroline-5-carboxylate reductase HHAL_RS04825
Alternative steps:
argA N-acylglutamate synthase HHAL_RS10335 HHAL_RS10235
argB N-acylglutamate kinase HHAL_RS11595 HHAL_RS10335
argC N-acylglutamylphosphate reductase HHAL_RS04505
argD N-acetylornithine aminotransferase HHAL_RS03740 HHAL_RS04195
argE N-acetylornithine deacetylase HHAL_RS10330
argJ ornithine acetyltransferase HHAL_RS10235
argX glutamate--LysW ligase HHAL_RS01265
cyclodeaminase ornithine cyclodeaminase
lysJ [LysW]-glutamate-semialdehyde aminotransferase HHAL_RS04195 HHAL_RS03740
lysK [LysW]-ornithine hydrolase
lysW 2-aminoadipate/glutamate carrier protein
lysY [LysW]-glutamate-6-phosphate reductase HHAL_RS04505
lysZ [LysW]-glutamate kinase HHAL_RS11595
OAT L-ornithine 5-aminotransferase HHAL_RS04195 HHAL_RS03740

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