ENZYME entry: EC 2.5.1.21

Accepted Name
Squalene synthase.
Alternative Name(s)
Farnesyl-diphosphate farnesyltransferase.
Farnesyltransferase.
Presqualene synthase.
Presqualene-diphosphate synthase.
Squalene synthetase.
Reaction catalysed
  • 2 farnesyl diphosphate <=> diphosphate + presqualene diphosphate
  • Presqualene diphosphate + NAD(P)H <=> squalene + diphosphate + NAD(P)(+)
Cofactor(s)
Manganese or magnesium.
Comment(s)
  • This microsomal enzyme catalyzes the first committed step in the biosynthesis of sterols.
  • In the absence of NAD(P)H, presqualene diphosphate (PSPP) is accumulated.
  • When NAD(P)H is present, presqualene diphosphate does not dissociate from the enzyme during the synthesis of squalene from farnesyl diphosphate (FPP).
  • High concentrations of FPP inhibit the production of squalene but not of PSPP.
Cross-references
PROSITEPDOC00802
BRENDA2.5.1.21
EC2PDB2.5.1.21
ExplorEnz2.5.1.21
PRIAM enzyme-specific profiles2.5.1.21
KEGG Ligand Database for Enzyme Nomenclature2.5.1.21
IUBMB Enzyme Nomenclature2.5.1.21
IntEnz2.5.1.21
MEDLINEFind literature relating to 2.5.1.21
MetaCyc2.5.1.21
UniProtKB/Swiss-Prot
P53799, FDFT_ARATH;  Q752X9, FDFT_ASHGO;  Q32KR6, FDFT_BOVIN;  
P78589, FDFT_CANAX;  Q9HGZ6, FDFT_CANGA;  O74165, FDFT_CYBJA;  
Q54DR1, FDFT_DICDI;  P37268, FDFT_HUMAN;  P53798, FDFT_MOUSE;  
Q7S4Z6, FDFT_NEUCR;  P53800, FDFT_NICBE;  Q5R6U3, FDFT_PONAB;  
Q02769, FDFT_RAT;  P36596, FDFT_SCHPO;  Q92459, FDFT_USTMA;  
Q9Y753, FDFT_YARLI;  P29704, FDFT_YEAST;  

View entry in original ENZYME format
View entry in raw text format (no links)

All UniProtKB/Swiss-Prot entries referenced in this entry, with possibility to download in different formats, align etc.
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 2.5.1.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 2.5.-.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 2.-.-.-