Heptaprenyl diphosphate synthase

In enzymology, a heptaprenyl diphosphate synthase (EC 2.5.1.30) is an enzyme that catalyzes the chemical reaction

(2E,6E)-farnesyl diphosphate + 4 isopentenyl diphosphate ${\displaystyle \rightleftharpoons }$ 4 diphosphate + all-trans-heptaprenyl diphosphate

heptaprenyl diphosphate synthase
Identifiers
EC no.	2.5.1.30
CAS no.	74506-59-5
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Thus, the two substrates of this enzyme are (2E,6E)-farnesyl diphosphate and isopentenyl diphosphate, whereas its two products are diphosphate and all-trans-heptaprenyl diphosphate.

This enzyme belongs to the family of transferases, specifically those transferring aryl or alkyl groups other than methyl groups. The systematic name of this enzyme class is (2E,6E)-farnesyl-diphosphate:isopentenyl-diphosphate farnesyltranstransferase (adding 4 isopentenyl units). Other names in common use include all-trans-heptaprenyl-diphosphate synthase, heptaprenyl pyrophosphate synthase, and heptaprenyl pyrophosphate synthetase. This enzyme participates in biosynthesis of steroids.

Structural studies

As of late 2007, 11 structures have been solved for this class of enzymes, with PDB accession codes 2E8T, 2E8U, 2E8V, 2E8W, 2E8X, 2E90, 2E91, 2E92, 2E93, 2E94, and 2E95.