Download MendeleyStructural insights into a bacterial terpene cyclase fused with haloacid Dehalogenase-like phosphatase.
Fujiyama, K., Takagi, H., Vo, N.N.Q., Morita, N., Nogawa, T., Takahashi, S.(2025) Chem Sci 16: 15310-15319
- PubMed: 40852458
- DOI: https://doi.org/10.1039/d5sc04719f
- Primary Citation of Related Structures:
9M7D, 9M7E, 9M7F - PubMed Abstract:
Terpene cyclases (TCs), consisting of various combinations of α, β, and γ domains, have been extensively studied. Recently, non-canonical enzymes comprising a TCβ domain and a haloacid dehalogenase (HAD)-like domain (referred to as HAD-TCβ) have been discovered. However, their overall structure remains unclear. In this study, we determined the co-crystal structures of drimenol synthase from Aquimarina spongiae (AsDMS), which catalyzes the conversion of farnesyl pyrophosphate (1) into drimenol (2). Crystallographic analyses of the enzyme bound to substrates 1 and drimenyl monophosphate (3) demonstrated that the TCβ domain catalyzes a class II cyclization reaction initiated by protonation, whereas the HAD domain catalyzes a phosphatase-like dephosphorylation reaction dependent on a divalent metal. Crystallographic and gel filtration analyses revealed that AsDMS adopts a dimeric assembly. This dimerization positioned the TCβ and HAD domains to facilitate efficient substrate transfer via electrostatic substrate channeling. Furthermore, to investigate the structure-function relationship of the AsDMS TCβ domain, we used AlphaFold2 to model the structure of the fungal albicanol (4) synthase. Comparative analysis of active-site residues between AsDMS and fungal 4-synthase enabled rational protein engineering, converting AsDMS activity from 2-synthase to 4-synthase. This study provides insights into the biosynthesis of valuable drimane-type sesquiterpenes via targeted mutagenesis.
- Natural Product Biosynthesis Research Unit, RIKEN Center for Sustainable Resource Science Wako Saitama 351-0198 Japan shunjitaka@riken.jp.
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