GapMind for Amino acid biosynthesis


L-histidine biosynthesis in Haloferax volcanii DS2

Best path

prs, hisG, hisI, hisE, hisA, hisF, hisH, hisB, hisC, hisN?, hisD


Overview: Histidine biosynthesis in GapMind is based on the MetaCyc pathway (link).

11 steps (11 with candidates)

Or see definitions of steps

Step Description Best candidate 2nd candidate Known gap?
prs ribose-phosphate diphosphokinase C498_RS18815  
hisG ATP phosphoribosyltransferase C498_RS18460  
hisI phosphoribosyl-ATP pyrophosphatase C498_RS15990 C498_RS08395  
hisE phosphoribosyl-AMP cyclohydrolase C498_RS17565 C498_RS08395  
hisA 1-(5-phosphoribosyl)-5-[(5-phosphoribosylamino)methylideneamino]imidazole-4-carboxamide isomerase C498_RS17545 C498_RS13085  
hisF imidazole glycerol phosphate synthase, cyclase subunit C498_RS13085 C498_RS17545  
hisH imidazole glycerol phosphate synthase, amidotransferase subunit C498_RS15925 C498_RS13085  
hisB imidazoleglycerol-phosphate dehydratase C498_RS17535  
hisC histidinol-phosphate aminotransferase C498_RS11865 C498_RS15240  
hisN? histidinol-phosphate phosphatase C498_RS17535 C498_RS02145 known gap
hisD histidinal/histidinol dehydrogenase C498_RS08395  

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.



Related tools

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