Abietadiene synthase

abietadiene synthase
Identifiers
EC number	4.2.3.18
CAS number	157972-08-2
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 / EGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, an abietadiene synthase (EC 4.2.3.18) is an enzyme that catalyzes the chemical reaction

(+)-copalyl diphosphate $\rightleftharpoons$ (−)-abietadiene + diphosphate

Hence, this enzyme has one substrate, (+)-copalyl diphosphate, and two products, (−)-abietadiene and diphosphate.

This enzyme belongs to the family of lyases, specifically those carbon-oxygen lyases acting on phosphates. The systematic name of this enzyme class is (+)-copalyl-diphosphate diphosphate-lyase [cyclizing (−)-abietadiene-forming]. This enzyme is also called copalyl-diphosphate diphosphate-lyase (cyclizing). This enzyme participates in diterpenoid biosynthesis.

It has recently been shown (Keeling, et al., 2011) that the orthologous gene in Norway spruce (Picea abies) does not produce abietadiene directly, but instead produces a thermally unstable allylic tertiary alcohol 13-hydroxy-8(14)- abietene, which readily dehydrates to abietadiene, levopimaradiene, palustradiene, and neoabietadiene, when analyzed by the commonly used gas chromatography. This has been confirmed in the other conifer species, lodgepole pine ("Pinus contorta") and Jack pine ("Pinus banksiana") (Hall et al., 2013).

References

• RB; Flory, JE; Jetter, R; Ravn, MM; Lee, HJ; Coates, RM; Croteau, RB (2000). "Abietadiene synthase from grand fir (Abies grandis): characterization and mechanism of action of the "pseudomature" recombinant enzyme". Biochemistry. 39 (50): 15592–602. doi:10.1021/bi001997l. PMID 11112547.
• Peters RJ, Ravn MM, Coates RM, Croteau RB (2001). "Bifunctional abietadiene synthase: free diffusive transfer of the (+)-copalyl diphosphate intermediate between two distinct active sites". J. Am. Chem. Soc. 123 (37): 8974–8. doi:10.1021/ja010670k. PMID 11552804.
• Peters RJ, Croteau RB (2002). "Abietadiene synthase catalysis: mutational analysis of a prenyl diphosphate ionization-initiated cyclization and rearrangement". Proc. Natl. Acad. Sci. U.S.A. 99 (2): 580–4. doi:10.1073/pnas.022627099. PMC 117348. PMID 11805316.
• Peters RJ, Croteau RB (2002). "Abietadiene synthase catalysis: conserved residues involved in protonation-initiated cyclization of geranylgeranyl diphosphate to (+)-copalyl diphosphate". Biochemistry. 41 (6): 1836–42. doi:10.1021/bi011879d. PMID 11827528.
• Ravn MM, Peters RJ, Coates RM, Croteau R (2002). "Mechanism of abietadiene synthase catalysis: stereochemistry and stabilization of the cryptic pimarenyl carbocation intermediates". J. Am. Chem. Soc. 124 (24): 6998–7006. doi:10.1021/ja017734b. PMID 12059223.
• Keeling CI, Madilao LL, Zerbe P, Dullat HK, Bohlmann J (2011). "The primary diterpene synthase products of Picea abies levopimaradiene/abietadiene synthase (PaLAS) are epimers of a thermally unstable diterpenol". J. Biol. Chem. 286 (24): 21145–21153. doi:10.1074/jbc.M111.245951. PMC 3122176. PMID 21518766.
• Hall DE, Zerbe P, Jancsik S, Quesada AL, Dullat H, Madilao LL, Yuen M, Bohlmann J (2013). "Evolution of conifer diterpene synthases: diterpene resin acid biosynthesis in lodgepole pine and jack pine involves monofunctional and bifunctional diterpene synthases". Plant Physiol. 161 (2): 600–616. doi:10.1104/pp.112.208546. PMC 3561007. PMID 23370714.