If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Locations of Mapped Genes:
|Superclasses:||Biosynthesis → Amino Acids Biosynthesis → Proteinogenic Amino Acids Biosynthesis → L-histidine Biosynthesis|
Pathway Summary from MetaCyc:
The genes necessary for histidine biosynthesis have been identified in many bacteria, fungi, plants, and archaea. The pathway in all of these organisms is identical, with small differences in some of the enzymes used. Histidine is an essential amino acid, and is not synthesized by mammals.
A few differences between different organisms concern whether the enzymes are mono- or bifunctional. One such case is the enzyme histidinol-phosphate phosphatase (EC 22.214.171.124). Some organisms, including Escherichia coli K-12, Salmonella enterica enterica serovar Typhimurium and Haemophilus influenzae, have a bifunctional enzyme, with the C-terminal domain exhibiting imidazoleglycerol-phosphate dehydratase (EC 126.96.36.199) activity. These enzymes belong to the DDDD phosphohydrolase/phosphotransferase superfamily. Other organisms have separate monofunctional enzymes catalyzing these two reactions. Monofunctional histidinol-phosphate phosphatases belong to either the PHP (polymerase and histidinol phosphatase) superfamily, as in the case of Bacillus subtilis, Saccharomyces cerevisiae and Thermus thermophilus HB8 [Omi04], or to the DDDD superfamily, as in the case of the archaeon Thermococcus onnurineus NA1 [Lee08].
Another such case concerns the conversion of phosphoribulosylformimino-AICAR-P (BBM III) to D-erythro-imidazole-glycerol-phosphate (IGP) and 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxamide (AICAR). This process requires two catalytic functions, including the transfer of an amide from L-glutamine and a cyclization reaction. In prokaryotes, these two catalytic activities are encoded by two genes whose products form a complex. In yeast and plants, this conversion is catalyzed by a single bifunctional enzyme.
Pathway Evidence Glyph:
Key to pathway glyph edge colors:
An enzyme catalyzing this reaction is present in this organism
An enzyme catalyzing this reaction was identified in this organism by the Pathway Hole Filler
The reaction and any enzyme that catalyzes it (if one has been identified) is unique to this pathway
Omi04: Omi R, Goto M, Nakagawa N, Miyahara I, Hirotsu K (2004). "Expression, purification and preliminary X-ray characterization of histidinol phosphate phosphatase." Acta Crystallogr D Biol Crystallogr 60(Pt 3);574-6. PMID: 14993698
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