Birth of Archaeal Cells: Molecular Phylogenetic Analyses of G1P Dehydrogenase, G3P Dehydrogenases, and Glycerol Kinase Suggest Derived Features of Archaeal Membranes Having G1P Polar Lipids.

Shin-Ichi Yokobori,Akihiko Yamagishi,Satoshi Akanuma,Yoshiki Nakajima

doi:10.1155/2016/1802675

Shin-Ichi Yokobori, Akihiko Yamagishi + Show 2 more

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https://doi.org/10.1155/2016/1802675

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Abstract

Bacteria and Eukarya have cell membranes with sn-glycerol-3-phosphate (G3P), whereas archaeal membranes contain sn-glycerol-1-phosphate (G1P). Determining the time at which cells with either G3P-lipid membranes or G1P-lipid membranes appeared is important for understanding the early evolution of terrestrial life. To clarify this issue, we reconstructed molecular phylogenetic trees of G1PDH (G1P dehydrogenase; EgsA/AraM) which is responsible for G1P synthesis and G3PDHs (G3P dehydrogenase; GpsA and GlpA/GlpD) and glycerol kinase (GlpK) which is responsible for G3P synthesis. Together with the distribution of these protein-encoding genes among archaeal and bacterial groups, our phylogenetic analyses suggested that GlpA/GlpD in the Commonote (the last universal common ancestor of all extant life with a cellular form, Commonote commonote) acquired EgsA (G1PDH) from the archaeal common ancestor (Commonote archaea) and acquired GpsA and GlpK from a bacterial common ancestor (Commonote bacteria). In our scenario based on this study, the Commonote probably possessed a G3P-lipid membrane synthesized enzymatically, after which the archaeal lineage acquired G1PDH followed by the replacement of a G3P-lipid membrane with a G1P-lipid membrane.

Highlights

Archaea is one of the three domains covering all extant terrestrial life
Euryarchaeal, thaumarchaeal, and bacterial G1P dehydrogenase (G1PDH) appear as subgroups of crenarchaeal G1PDHs
Euryarchaeal and thaumarchaeal G1PDHs form a group in this tree, 31 bacterial G1PDHs form a distinct monophyletic group separated from the G1PDHs of euryarchaeal and thaumarchaeal ones

Summary

Introduction

Archaea is one of the three domains covering all extant terrestrial life. Woese et al [1] suggested that Bacteria, Archaea, and Eukarya are distinct monophyletic groups based on the small subunit ribosomal RNA tree. It has been proposed that Eukarya (eukaryotes) are derived from a certain archaeal branch, such as the TACK superphylum [2] or Lokiarchaeota [3, 4]. In any of these three cases, most hypotheses placed the LUCA (last universal common ancestor), known as the Commonote [5], between the Bacteria and a group formed by Archaea and Eukarya. We prefer to use the term “Commonote” rather than LUCA or progenote, since the definition of Commonote is the last universal common ancestor having a cellular membrane [5], as we believe that the last universal common ancestor was a cellular organism. We use the terms Commonote commonote, Commonote archaea, and Commonote bacteria referring to the last common ancestral species of all living organisms (formerly Commonote) and of Archaea and Bacteria, as proposed in Akanuma et al [6]

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