Epsilon glutathione transferases possess a unique class-conserved subunit interface motif that directly interacts with glutathione in the active site.

Jantana Wongsantichon,Robert C Robinson,Albert J Ketterman

doi:10.1042/bsr20150183

Abstract

Epsilon class glutathione transferases (GSTs) have been shown to contribute significantly to insecticide resistance. We report a new Epsilon class protein crystal structure from Drosophila melanogaster for the glutathione transferase DmGSTE6. The structure reveals a novel Epsilon clasp motif that is conserved across hundreds of millions of years of evolution of the insect Diptera order. This histidine-serine motif lies in the subunit interface and appears to contribute to quaternary stability as well as directly connecting the two glutathiones in the active sites of this dimeric enzyme.

Highlights

Glutathione transferases (GSTs) are a superfamily of proteins found in all cellular organisms, which usually exist as multiple isoforms [1,2]
Within the Drosophila melanogaster glutathione transferase epsilon 6 (DmGSTE6) structure we have identified a motif that has been conserved across millions of years of evolution
We have determined the structure of DmGSTE6 to supplement the currently known Epsilon structures (Figure 1, Table 1)

Summary

Introduction

Glutathione transferases (GSTs) are a superfamily of proteins found in all cellular organisms, which usually exist as multiple isoforms [1,2]. Amino acid sequence alignments predict that this motif may be conserved in the Epsilon class GSTs. The structural motif appears to affect protein dynamics and influences substrate specificity, enzyme activity and protein stability.

Results

Conclusion