期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 114, 期 29, 页码 E6005-E6014出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1705567114
关键词
sesterterpene biosynthesis; plant natural products; cyclization mechanism; convergent evolution; Brassicaceae
资金
- US National Science Foundation [CHE-1565933]
- United Kingdom Biotechnological and Biological Sciences Research Council Institute Strategic Programme Grant Understanding and Exploiting Plant and Microbial Metabolism [BB/J004561/1]
- John Innes Foundation
- NIH Genome to Natural Products Network Award [U101GM110699]
- European Commission Marie Sklodowska-Curie Individual Fellowship [H2020-MSCA-IF-EF-ST-702478-TRIGEM]
- VENI Grant from The Netherlands Organization for Scientific Research [863.15.002]
- Graduate School for Experimental Plant Sciences
- BBSRC [BBS/E/J/000PR9790, BBS/E/J/000PR9794] Funding Source: UKRI
- Biotechnology and Biological Sciences Research Council [BBS/E/J/000PR9790, BBS/E/J/000PR9794, BBS/E/J/00000614] Funding Source: researchfish
Sesterterpenoids are a rare terpene class harboring untapped chemodiversity and bioactivities. Their structural diversity originates primarily from the scaffold-generating sesterterpene synthases (STSs). In fungi, all six known STSs are bifunctional, containing C-terminal trans-prenyltransferase (PT) and N-terminal terpene synthase (TPS) domains. In plants, two colocalized PT and TPS gene pairs from Arabidopsis thaliana were recently reported to synthesize sesterterpenes. However, the landscape of PT and TPS genes in plant genomes is unclear. Here, using a customized algorithm for systematically searching plant genomes, we reveal a suite of physically colocalized pairs of PT and TPS genes for the biosynthesis of a large sesterterpene repertoire in the wider Brassicaceae. Transient expression of seven TPSs from A. thaliana, Capsella rubella, and Brassica oleracea in Nicotiana benthamiana yielded fungal-type sesterterpenes with tri-, tetra-, and pentacyclic scaffolds, and notably (-)-ent-quiannulatene, an enantiomer of the fungal metabolite (+)-quiannulatene. Protein and structural modeling analysis identified an amino acid site implicated in structural diversification. Mutation of this site in one STS (AtTPS19) resulted in premature termination of carbocation intermediates and accumulation of bi-, tri-, and tetracyclic sesterterpenes, revealing the cyclization path for the pentacyclic sesterterpene (-)-retigeranin B. These structural and mechanistic insights, together with phylogenetic analysis, suggest convergent evolution of plant and fungal STSs, and also indicate that the colocalized PT-TPS gene pairs in the Brassicaceae may have originated from a common ancestral gene pair present before speciation. Our findings further provide opportunities for rapid discovery and production of sesterterpenes through metabolic and protein engineering.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据