4-Hydroxy-3-methylbut-2-enyl diphosphate reductase (, ''isopentenyl-diphosphate:NADP+ oxidoreductase'', ''LytB'', ''(E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate reductase'', ''HMBPP reductase'', ''IspH'', ''LytB/IspH'') is an enzyme in the

non-mevalonate pathway The non-mevalonate pathway—also appearing as the mevalonate-independent pathway and the 2-''C''-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate (MEP/DOXP) pathway—is an alternative metabolic pathway for the biosynthesis of the i ...

. It acts upon

(E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate (''E'')-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP or HMB-PP) is an intermediate of the MEP pathway (non-mevalonate pathway) of isoprenoid biosynthesis. The enzyme HMB-PP synthase (GcpE, IspG) catalyzes the conversion of 2-''C''-methyl- ...

(or "HMB-PP"). : (1)

isopentenyl diphosphate Isopentenyl pyrophosphate (IPP, isopentenyl diphosphate, or IDP) is an isoprenoid precursor. IPP is an intermediate in the classical, HMG-CoA reductase pathway (commonly called the mevalonate pathway) and in the ''non-mevalonate'' MEP pathway of i ...

+ NAD(P)⁺ + H₂O

\rightleftharpoons

(E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate + NAD(P)H + H⁺ : (2)

dimethylallyl diphosphate Dimethylallyl pyrophosphate (DMAPP; or alternatively, dimethylallyl diphosphate (DMADP); also isoprenyl pyrophosphate) is an isoprenoid precursor. It is a product of both the mevalonate pathway and the MEP pathway of isoprenoid precursor biosynt ...

+ NAD(P)⁺ + H₂O

\rightleftharpoons

(E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate + NAD(P)H + H⁺ 4-Hydroxy-3-methylbut-2-enyl diphosphate reductase is an

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...

protein that contains either a Fe-4Sor a Fe-4Scluster.

References

EC 1.17.1 {{enzyme-stub