geranylgeranyl pyrophosphate synthase; GGPP synthase; GGPPSase; geranylgeranyl diphosphate synthase; geranyltranstransferase (GGPS1)

Function

• catalyzes trans-addition of 3 isopentenyl pyrophosphates onto dimethylallyl pyrophosphate to form geranylgeranyl pyrophosphate, a precursor of carotenoids & geranylated proteins
• subject to product inhibition by geranylgeranyl pyrophosphate
• isoprenoid biosynthesis;
  • farnesyl pyrophosphate biosynthesis;
    • farnesyl pyrophosphate from geranyl pyrophosphate & isopentenyl pyrophosphate: step 1/1
  • geranyl pyrophosphate biosynthesis;
    • geranyl pyrophosphate from dimethylallyl pyrophosphate & isopentenyl pyrophosphate: step 1/1
  • geranylgeranyl pyrophosphate biosynthesis;
    • geranylgeranyl pyrophosphate from farnesyl pyrophosphate & isopentenyl pyrophosphate: step 1/1

dimethylallyl pyrophosphate + isopentenyl pyrophosphate = pyrophosphate + geranyl pyrophosphate

geranyl pyrophosphate + isopentenyl pyrophosphate = pyrophosphate + (2E,6E)-farnesyl pyrophosphate

trans,trans-farnesyl pyrophosphate + isopentenyl pyrophosphate = pyrophosphate + geranylgeranyl pyrophosphate

Kinetic parameters:

• KM=3 uM for isopentenyl pyrophosphate
• KM=4.2 uM for farnesyl pyrophosphate

Cofactor:

• binds 3 Mg+2 (probable)

Structure

• homohexamer; trimer of homodimers
• belongs to the FPP/GGPP synthase family

Compartment

cytoplasm

Expression

• abundantly expressed in testis
• found in other tissues to a lower extent

More general terms

• dimethylallyltransferase
• prenyltransferase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=9453
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:9453
• OMIM: https://mirror.omim.org/entry/606982
• UniProt: http://www.uniprot.org/uniprot/O95749.html