AC   MF_00191;
DC   Protein; auto
TR   HAMAP; MF_00191; -; 1; level=0
XX
Names: IspH
XX
ID   ISPH
DE   RecName: Full=4-hydroxy-3-methylbut-2-enyl diphosphate reductase;
DE            Short=HMBPP reductase;
DE            EC=1.17.7.4;
GN   Name=ispH;
XX
CC   -!- FUNCTION: Catalyzes the conversion of 1-hydroxy-2-methyl-2-(E)-butenyl
CC       4-diphosphate (HMBPP) into a mixture of isopentenyl diphosphate (IPP)
CC       and dimethylallyl diphosphate (DMAPP). Acts in the terminal step of the
CC       DOXP/MEP pathway for isoprenoid precursor biosynthesis.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=H2O + isopentenyl diphosphate + 2 oxidized [2Fe-2S]-
CC         [ferredoxin] = (2E)-4-hydroxy-3-methylbut-2-enyl diphosphate + 2 H(+)
CC         + 2 reduced [2Fe-2S]-[ferredoxin]; Xref=Rhea:RHEA:24488, Rhea:RHEA-
CC         COMP:10000, Rhea:RHEA-COMP:10001, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:33737, ChEBI:CHEBI:33738,
CC         ChEBI:CHEBI:128753, ChEBI:CHEBI:128769; EC=1.17.7.4;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=dimethylallyl diphosphate + H2O + 2 oxidized [2Fe-2S]-
CC         [ferredoxin] = (2E)-4-hydroxy-3-methylbut-2-enyl diphosphate + 2 H(+)
CC         + 2 reduced [2Fe-2S]-[ferredoxin]; Xref=Rhea:RHEA:24825, Rhea:RHEA-
CC         COMP:10000, Rhea:RHEA-COMP:10001, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:33737, ChEBI:CHEBI:33738,
CC         ChEBI:CHEBI:57623, ChEBI:CHEBI:128753; EC=1.17.7.4;
case <FTGroup:1>
CC   -!- COFACTOR:
CC       Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883;
CC       Note=Binds 1 [4Fe-4S] cluster per subunit.;
end case
CC   -!- PATHWAY: Isoprenoid biosynthesis; dimethylallyl diphosphate
CC       biosynthesis; dimethylallyl diphosphate from (2E)-4-hydroxy-3-
CC       methylbutenyl diphosphate: step 1/1.
CC   -!- PATHWAY: Isoprenoid biosynthesis; isopentenyl diphosphate biosynthesis
CC       via DXP pathway; isopentenyl diphosphate from 1-deoxy-D-xylulose 5-
CC       phosphate: step 6/6.
case <OC:Enterobacterales>
CC   -!- SUBUNIT: Homodimer.
end case
CC   -!- SIMILARITY: Belongs to the IspH family.
XX
DR   Pfam; PF02401; LYTB; 1; trigger=no
DR   NCBIfam; TIGR00216; IspH_lytB; 1; trigger=no
XX
case <FTGroup:1>
KW   4Fe-4S
KW   Iron
KW   Iron-sulfur
KW   Metal-binding
end case
KW   Isoprene biosynthesis
KW   Oxidoreductase
XX
case <FTGroup:1>
GO   GO:0051539; F:4 iron, 4 sulfur cluster binding
end case
GO   GO:0051745; F:4-hydroxy-3-methylbut-2-en-1-yl diphosphate reductase activity
GO   GO:0019288; P:isopentenyl diphosphate biosynthetic process, methylerythritol 4-phosphate pathway
GO   GO:0016114; P:terpenoid biosynthetic process
GO   GO:0050992; P:dimethylallyl diphosphate biosynthetic process
XX
FT   From: ISPH_ECOLI (P62623)
FT   BINDING         225..227
FT                   /ligand="substrate"
FT   Condition: S-x-N
FT   ACT_SITE        126
FT                   /note="Proton donor"
FT   Condition: E
FT   BINDING         12
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT   Group: 1; Condition: C
FT   BINDING         96
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT   Group: 1; Condition: C
FT   BINDING         197
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT   Group: 1; Condition: C
FT   BINDING         41
FT                   /ligand="substrate"
FT   Condition: H
FT   BINDING         74
FT                   /ligand="substrate"
FT   Optional; Condition: H
FT   BINDING         124
FT                   /ligand="substrate"
FT   Condition: H
FT   BINDING         167
FT                   /ligand="substrate"
FT   Condition: [TS]
FT   BINDING         269
FT                   /ligand="substrate"
FT   Condition: S
XX
Size: 273-417;
Related: None;
Template: P62623; O67625; Q55643;
Scope:
 Bacteria
Fusion:
 Nter: None
 Cter: <S1>
Duplicate: in BRADU, MYCBO, MYCTU, RHOPA
Plasmid: None
Comments: None
XX
# Revision 1.48 2023/06/01
//