Barik Sailen
3780 Pelham Drive, Mobile, AL 36619, USA.
Int J Mol Sci. 2020 Dec 18;21(24):9662. doi: 10.3390/ijms21249662.
This review focuses on the molecular signatures of protein structures in relation to evolution and survival in global warming. It is based on the premise that the power of evolutionary selection may lead to thermotolerant organisms that will repopulate the planet and continue life in general, but perhaps with different kinds of flora and fauna. Our focus is on molecular mechanisms, whereby known examples of thermoresistance and their physicochemical characteristics were noted. A comparison of interactions of diverse residues in proteins from thermophilic and mesophilic organisms, as well as reverse genetic studies, revealed a set of imprecise molecular signatures that pointed to major roles of hydrophobicity, solvent accessibility, disulfide bonds, hydrogen bonds, ionic and π-electron interactions, and an overall condensed packing of the higher-order structure, especially in the hydrophobic regions. Regardless of mutations, specialized protein chaperones may play a cardinal role. In evolutionary terms, thermoresistance to global warming will likely occur in stepwise mutational changes, conforming to the molecular signatures, such that each "intermediate" fits a temporary niche through punctuated equilibrium, while maintaining protein functionality. Finally, the population response of different species to global warming may vary substantially, and, as such, some may evolve while others will undergo catastrophic mass extinction.
本综述聚焦于蛋白质结构的分子特征与全球变暖下的进化及生存的关系。其基于这样一个前提:进化选择的力量可能会导致耐热生物出现,这些生物将重新在地球上繁衍,并总体上延续生命,但或许会有不同种类的动植物。我们关注的是分子机制,通过这些机制可发现已知的耐热例子及其物理化学特性。对嗜热生物和嗜温生物蛋白质中不同残基相互作用的比较以及反向遗传学研究,揭示了一组不精确的分子特征,这些特征表明疏水性、溶剂可及性、二硫键、氢键、离子和π电子相互作用以及高阶结构的整体紧密堆积起着主要作用,尤其是在疏水区域。无论有无突变,专门的蛋白质伴侣可能都起着关键作用。从进化角度看,对全球变暖的耐热性可能会通过符合分子特征的逐步突变变化而出现,使得每个“中间体”通过间断平衡适应一个临时生态位,同时保持蛋白质功能。最后,不同物种对全球变暖的种群反应可能有很大差异,因此,一些物种可能会进化,而另一些则会遭受灾难性的大规模灭绝。