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.
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