Phi Class of Glutathione S-transferase Gene Superfamily Widely Exists in Nonplant Taxonomic Groups

Abstract

Glutathione S-transferases (GSTs) constitute a superfamily of enzymes involved in detoxification of noxious compounds and protection against oxidative damage. GST class Phi (GSTF), one of the important classes of plant GSTs, has long been considered as plant specific but was recently found in basidiomycete fungi. However, the range of nonplant taxonomic groups containing GSTFs remains unknown. In this study, the distribution and phylogenetic relationships of nonplant GSTFs were investigated. We identified GSTFs in ascomycete fungi, myxobacteria, and protists Naegleria gruberi and Aureococcus anophagefferens. GSTF occurrence in these bacteria and protists correlated with their genome sizes and habitats. While this link was missing across ascomycetes, the distribution and abundance of GSTFs among ascomycete genomes could be associated with their lifestyles to some extent. Sequence comparison, gene structure, and phylogenetic analyses indicated divergence among nonplant GSTFs, suggesting polyphyletic origins during evolution. Furthermore, in silico prediction of functional partners suggested functional diversification among nonplant GSTFs.

Structural plasticity among glutathione transferase Phi members: natural combination of catalytic residues confers dual biochemical activities

“…Previous phylogenetic analyses indicated that GSTFs are only found in a few restricted lineages, mostly higher plants and fungi and in some bacteria and protists . Among photosynthetic organisms, the number of genes ranges from 1 in S. moellendorffii to 38 in T. aestivum which strongly argues for the occurrence of gene duplication in a species‐specific manner .…”

Functional, Structural and Biochemical Features of Plant Serinyl-Glutathione Transferases

“…Some of these classes are found among different kingdoms, such as Zeta or Theta classes whereas Lambda, Tau and DHAR classes are specific to plants. The Phi class is sometimes presented in the literature as specific to the plant kingdom but similar sequences have been identified in some fungi, bacteria, and protists (Morel et al, 2013; Munyampundu et al, 2016). Although it has some limitations, the primary sequence remains to date the most convenient criterion for classifying these proteins.…”

Genome-wide identification and expression profiling of glutathione transferase gene family under multiple stresses and hormone treatments in wheat (Triticum aestivum L.)

“…Fourteen classes have been confirmed based on phylogenetic analysis of all GSTs in eight eukaryote photosynthetic organisms, among them, eight classes are more widespread and contain tau (GSTU), phi (GSTF), lambda (GSTL), dehydroascorbate reductase (DHAR), theta (GSTT), γ-subunit of translation elongation factor (EF1G), zeta (GSTZ) and tetrachloro-hydroquinone dehalogenase (TCHQD) classes [9]. The phi and tau classes usually have more members than others in GST family, and the tau, phi, lambda and DHAR classes have long been considered as plant-specific, while the similar sequences of phi class have been discovered in some fungi and bacteria in recent years [10–12].…”