Targeting active site residues and structural anchoring positions in terpene synthases.

Anwei Hou,Jeroen S Dickschat

doi:10.3762/bjoc.17.161

Abstract

The sesterterpene synthase SmTS1 from Streptomyces mobaraensis contains several unusual residues in positions that are otherwise highly conserved. Site-directed mutagenesis experiments for these residues are reported that showed different effects, resulting in some cases in an improved catalytic activity, but in other cases in a loss of enzyme function. For other enzyme variants a functional switch was observed, turning SmTS1 from a sesterterpene into a diterpene synthase. This article gives rational explanations for these findings that may generally allow for protein engineering of other terpene synthases to improve their catalytic efficiency or to change their functions.

Highlights

Terpenoids span more than 90,000 known compounds, which makes them by far the largest class of natural products [1]
All compounds are made from only two C5 building blocks, dimethylallyl diphosphate (DMAPP) and isopentenyl diphosphate (IPP), that can be fused by oligoprenyl diphosphate synthases to yield geranyl diphosphate (GPP, C10) as the precursor to monoterpenes, farnesyl diphosphate (FPP, C15) as sesquiterpene precursor, geranylgeranyl diphosphate (GGPP, C20) towards diterpenes, and geranylfarnesyl diphosphate (GFPP, C25) for sesterterpene biosynthesis
We have recently shown that the sum of the calculated van der Waals volumina (ΣVvdW) of the active site residues of TPSs can be calculated using a simple equation by Abraham and co-workers [18]

Summary

Introduction

Terpenoids span more than 90,000 known compounds, which makes them by far the largest class of natural products [1]. Site-directed mutagenesis experiments for these residues are reported that showed different effects, resulting in some cases in an improved catalytic activity, but in other cases in a loss of enzyme function.

Results

Conclusion