Converting S-limonene synthase to pinene or phellandrene synthases reveals the plasticity of the active site

Mutation N345A/L423A/S454A converts M. spicata limonene synthase to a pinene synthase, while a single mutation N345I converts it to a phellandrene synthase. Polar residues in the active pocket may be essential for limonene production by stabilizing the terpinyl cation.181