4-hydroxy-3-methylbut-2-en-1-yl diphosphate synthase

Template:Short description Template:Infobox enzyme In enzymology, a 4-hydroxy-3-methylbut-2-en-1-yl diphosphate synthase (HMB-PP synthase, IspG, Template:EC number) is an enzyme that catalyzes the chemical reaction

2-C-methyl-D-erythritol 2,4-cyclodiphosphate + protein-dithiol $\rightleftharpoons$ (E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate + H₂O + protein-disulfide

The substrate of this enzyme is 2-C-methyl-D-erythritol 2,4-cyclodiphosphate (MEcPP) and the product is (E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate (HMB-PP). Electrons are donated by two reduced ferredoxin proteins per reaction.

This enzyme participates in the MEP pathway (non-mevalonate pathway) of Isoprenoid precursor biosynthesis.

Nomenclature

This enzyme belongs to the family of oxidoreductases, specifically those acting on CH or CH₂ groups with a disulfide as acceptor. The systematic name of this enzyme class is (E)-4-hydroxy-3-methylbut-2-en-1-yl-diphosphate:protein-disulfide oxidoreductase (hydrating).

Further reading

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