Discovery and mechanistic study of coral-derived terpene synthases reveal insights into terpene scaffolds' orthologous evolution

Marine corals, rich in diverse terpenoids, are a promising resource for drug discovery, yet their potential is hindered by low supply. Recent reports on coral-derived terpene synthases (TSs) have confirmed that corals are indeed the primary producers of coral terpenoids, pointing us towards a solution for the low supply issue. However, only a few coral TSs have been functionally identified, lacking comprehensive studies on their mechanisms, phylogenetic relationships, and engineering applications. To address these gaps, we conducted genome mining to discover and study all TSs within the genome of the sea whip coral, Paramuricea clavata. We performed isotope labeling, protein crystallography, and quantum mechanics/molecular mechanics (QM/MM) calculations-guided mutations, particularly focusing on a biflorane synthase, PcTS1. These multifaceted experiments have elucidated the catalytic mechanisms of PcTS1 in detail. Furthermore, our phylogenetic analysis of coral TSs, which are crucial for the biosynthesis of structurally related terpene skeletons such as biflorane, eunicellane, and cembrane, has provided significant insights into the evolutionary development of terpene scaffolds. Based on these insights, we have applied evolution-based engineering efforts to PcTS1, successfully producing new terpene structures that are related to its mechanistic intermediates. This research not only establishes a connection between the chemical diversity of terpenes and coral genomes but also enhances our understanding of coral TSs from both mechanistic and evolutionary perspectives. In addition, this work offers a new research paradigm for the study of coral-derived terpenoids and inspires future high-quality coral sequencing efforts.