The enzyme has been characterized from Dysphania ambrosioides (American wormseed). Requires Mg2+. Mn2+ is less effective. The enzyme will also use (3R)-linalyl diphosphate. The reaction involves a 1,2-hydride shift. The 1-pro-S hydrogen of geranyl diphosphate is lost.
Poulose, A.J. and Croteau, R. γ-Terpinene synthetase: a key enzyme in the biosynthesis of aromatic monoterpenes. Arch. Biochem. Biophys.191 (1978) 400–411. [DOI] [PMID: 736574]
LaFever, R.E. and Croteau, R. Hydride shifts in the biosynthesis of the p-menthane monoterpenes α-terpinene, γ-terpinene, and β-phellandrene. Arch. Biochem. Biophys.301 (1993) 361–366. [DOI] [PMID: 8460944]