The Evolutionary History and Modern Diversity of Triterpenoid Cyclases.

Cyclic terpenoids are a class of lipid compounds containing immense structural and functional diversity, with many cyclic triterpenoids acting as regulators of the physical properties and spatial organization of lipid membranes. Cyclic terpenoids are also readily preserved as terpane fossils, such as steranes and hopanes, forming a rich record of the evolution of life on Earth. Formation of the multiple ring structure of all cyclic terpenoids is catalyzed by terpenoid cyclase enzymes, among which are whole clades of proteins-many from environmental metagenomes and uncultured organisms-whose substrates and products are completely unknown.

The evolutionary history and modern diversity of triterpenoid cyclases.

Cyclic terpenoids are a class of lipid compounds containing immense structural and functional diversity, with many cyclic triterpenoids acting as regulators of the physical properties and spatial organization of lipid membranes. Cyclic terpenoids are also readily preserved as terpane fossils, such as steranes and hopanes, forming a rich record of the evolution of life on Earth. Formation of the multiple ring structure of all cyclic terpenoids is catalyzed by terpenoid cyclase enzymes, among which are whole clades of proteins - many from environmental metagenomes and uncultured organisms - whose substrates and products are completely unknown.