Genetics and Proteomics of Polyextremophiles Existing in High Temperature

Extremophiles thrive under extreme environmental conditions, such as high/low temperatures (41–122 °C for thermophiles), where most life forms find it difficult to survive. These microorganisms are found functionally stable in deep-sea hydrothermal vents, peat bogs, hot springs, and even in surroundings consisting of acidic and alkaline substances. Thermophiles, constantly exposed to high temperatures, have developed adaptations in all macromolecules and complexes to remain efficient. Most significantly, thermophiles bring adaptability to proteins’ hydrogen bond networks, surface loops, secondary structure propensity, hydrophobicity, van der Wall and ionic interactions, and packing density. In addition to the above mechanisms, thermophiles undergo structure-stabilization and sequence-stabilization approaches and adaptation in the lipid composition of thermophilic membranes. Positive supertwists and a rise in GC base pairs in some places are two examples of DNA alterations seen in thermophiles. Moreover, histone binding patterns increase thermal resistance among them. The industrial importance of polyextremophiles in cosmetics, pharmaceutical, biotechnology, food, and beverage industries makes use of these enzymes and proteins extensively. Insights into the mechanisms of evolution and the inhabitation of life on Earth may be gained by studying the genetic systems that allow such bacteria to endure these extremes of temperature. Therefore, in this chapter, we will highlight the mechanisms adopted by thermophiles to stand in extreme temperature conditions by uncovering changes at their genomic and proteomic level. The present understanding of the protein adaptation processes of thermophiles will also be summarized, shedding light on the ways in which infections direct their protein machinery to live inside host cells.