Multi-omics Reveals The Thermal Adaptation Mechanism Of Thermophiles

Thermophiles can grow normally in high temperature environments,and their thermal adaptation mechanism has always been the focus of research.In recent years,studies on the status of microbial populations,cell structure,biomolecular structure and function,metabolites,etc.,have made the thermal adaptation mechanism of thermophiles gradually clear.With the development of genome sequencing and mass spectrometry technology,the continuous accumulation of data on the genome,transcriptome,proteome,interactome,and metabolome of thermophiles has made it possible to reveal the thermal adaptation mechanism of thermophiles from multi-omics perspective.This research comprehensively expounds the thermal adaptation mechanism of thermophiles from four levels: molecular structure,molecular function,network topology,and metabolic activity by identifying the corresponding characteristics of thermophiles' genome,transcriptome,proteome,protein interaction network and metabolic network.This study found that the stem region proportion and GC content of thermophilic m RNAs are significantly lower,but the purine AG content in the loop region is significantly higher,which not only promote the activity of m RNA translation,but also maintains their thermal stability.The contents of charged amino acids in thermophilic proteins are relatively high,and the contents of ?-helix and ?-sheet regions are also significantly higher,which makes the proteins form more compact structures to enhance their thermal stability.The folding rate and aggregation propensity of thermophilic proteins are both low,which guarantees their normal folding in high temperature environments.By comparing the transcriptomes and proteomes of thermophiles and mesophiles,it was found that 3pathways for the synthesis of purine nucleotides and 4 pathways for the synthesis of amino acids as well as 3 energy metabolism pathways in thermophiles are significantly enhanced,providing sufficient materials and energy to deal with heat.The heat response pathways(assisting proteins folding and degradation of misfolded proteins)are significantly enhanced,the assembly activities of ribosomes are weakened,and the translations of ribosomes are reduced,which contributes to the thermophilic adaption to high temperature environment.The comparison of protein-protein interaction networks shows that thermophiles have higher level of modularization in protein functions and can cope with complex high temperature environments.Bacterial chemotaxis and flagellar assembly metabolic pathways are common in thermophiles,which makes thermophiles able to adjust their microenvironments through prompt migration.In thermophiles there is no synthesis pathway for unsaturated fatty acids,while the synthesis pathway for saturated fatty acids is relatively active,increasing saturated fatty acid contents in cell membrane to enhance its rigidity and thermal stability.This study revealed the molecular mechanism of thermal adaptation from multiple omics levels,which is of great significance to the research and application of thermophiles.