GapMind for Amino acid biosynthesis


L-histidine biosynthesis in Sulfurihydrogenibium azorense Az-Fu1

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 SULAZ_RS01065  
hisG ATP phosphoribosyltransferase SULAZ_RS01940  
hisI phosphoribosyl-ATP pyrophosphatase SULAZ_RS01585 SULAZ_RS04990  
hisE phosphoribosyl-AMP cyclohydrolase SULAZ_RS01585 SULAZ_RS04990  
hisA 1-(5-phosphoribosyl)-5-[(5-phosphoribosylamino)methylideneamino]imidazole-4-carboxamide isomerase SULAZ_RS00435 SULAZ_RS07265  
hisF imidazole glycerol phosphate synthase, cyclase subunit SULAZ_RS07265 SULAZ_RS00435  
hisH imidazole glycerol phosphate synthase, amidotransferase subunit SULAZ_RS01865 SULAZ_RS07265  
hisB imidazoleglycerol-phosphate dehydratase SULAZ_RS04700  
hisC histidinol-phosphate aminotransferase SULAZ_RS05520  
hisN? histidinol-phosphate phosphatase SULAZ_RS04700 SULAZ_RS02345 known gap
hisD histidinal/histidinol dehydrogenase SULAZ_RS04990  

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