Abstract

ROLE OF MFE IN PROTEIN THERMOSTABILITY IN THERMOPHILES

*Dr. Sonali Patil

Abstract

Thermostability is the resistance to irreversibility of chemical or physical changes of a substance due to elevation in temperature. Protein thermostability is, therefore, the preservation of the unique structure and chemical properties of polypeptide chains under extreme temperatures. Thermophilic organisms provide a natural source of thermostable enzymes for industrial applications. Although thermostability-enhancing factors have been identified in other organisms, there was need to determine them in species of the Methylobacterium genus. This study aimed to determine factors that enhance thermostability in species of the Methylobacterium family. The protein thermostability was measured by optimum growth temperature, protein melting temperature (Tm), minimum folding energy (MFE) of RNA secondary structures. The increase in MFE values in Methylobacterium extorquens PA1 and AM1 calculated for predicted mRNA secondary structures correlated with the rate of nucleotide substitutions (r = 0.37). These correlations were statistically significant as confirmed by a t-test. Thus, it can be concluded that significant changes in MFE and possible higher thermostability of mRNA molecules and encoded proteins are under positive evolutionary selection in these microorganisms.

Keywords: Thermophilic organisms provide a natural source of thermostable enzymes for industrial applications.