Evidence of molecular adaptation to extreme environments and applicability to space environments

TL;DR

This study identifies gene signatures and proteins involved in hyperthermophile adaptation to extreme temperatures, using comparative genomics and developing a temperature prediction model, with implications for space environment applications.

Contribution

It introduces a software tool for extremophile genome analysis and identifies novel genes and proteins linked to thermal adaptation in hyperthermophiles.

Findings

Identification of conserved genes in hyperthermophiles

Discovery of a unique chaperone TF55 in archaea

Development of a temperature prediction model

Abstract

This is initial study of a gene signatures responsible for adapting microscopic life to the life in extreme Earth environments. We present a results on ID of the clusters of COGs common to several hyperthermophiles and exclusion of those common to a mesophile: E.coli.K12, will yield a group of proteins possibly involved in adaptation to life under extreme T. Methanogens stand out as the only group of organisms that have species capable of growth at 0C (M.frigidum and M.burtonii) and 110C (M.kandleri). Not all the components of heat adaptation can be attributed to novel genes, the chaperones known as heat shock proteins stabilize the enzymes under elevated temperature. Highly conserved chaperons found in bacteria and eukaryots are not present in hyperthermophilic Archea, rather, they have a unique chaperone TF55. Our aim is to use software which we specifically developed for extremophile genome comparative analyses in order to search for additional novel genes involved in hyperthermophile adaptation. The following hyperthermophile genomes incorporated in our software were used for these studies: M.jannaschii, M.kandleri, A.fulgidus and 3 species of Pyrococcus. Common genes were annotated and grouped according to their roles in cellular processes when information was available and proteins not previously implicated in the heat-adaptation of hyperthermophiles were identified. Additional experimental data is needed in order to learn more about these proteins. To address a non-gene based components of thermal adaptation, all sequenced extremophiles were analysed for their GC contents and aminoacid hydrophobicity. We develop a prediction model for optimal growth temperature.