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Adaptation at the Extremes of Life: Experimental Evolution with the Extremophile Archaeon Sulfolobus acidocaldarius
Published on: June 14, 2024
Patterns of temperature adaptation in proteins from Methanococcus and Bacillus
J H McDonald1, A M Grasso, L K Rejto
1Department of Biological Sciences, University of Delaware, Newwark 19716, USA. mcdonald@udel.edu
Molecular Biology and Evolution
|December 22, 1999
Summary
Organism protein sequences show temperature-dependent amino acid preferences. Comparing mesophiles and thermophiles in Bacillus and Methanococcus reveals distinct, genus-specific substitution patterns, influenced by DNA composition.
Area of Science:
- Molecular Biology
- Genomics
- Evolutionary Biology
Background:
- Organism adaptation to temperature involves changes in protein sequences.
- Previous studies on amino acid substitutions in mesophiles and thermophiles were limited by small datasets and species diversity.
- Asymmetrical amino acid substitution patterns suggest temperature-driven selection.
Purpose of the Study:
- To investigate temperature-specific amino acid substitution patterns in closely related genera.
- To compare these patterns between a bacterium (Bacillus) and an archaeon (Methanococcus).
- To identify potential influences of genomic factors, such as DNA composition, on these patterns.
Main Methods:
- Comparative analysis of a large number of protein sequences from mesophilic and thermophilic species within the genera Bacillus and Methanococcus.
- Examination of amino acid substitution patterns across various protein families.
- Correlation of substitution patterns with genomic features, specifically DNA G+C content.
Main Results:
- Both Bacillus and Methanococcus exhibit significant, genus-specific asymmetrical amino acid substitution patterns between mesophiles and thermophiles.
- Several amino acid pairs show opposing favored residues in thermophilic Bacillus versus thermophilic Methanococcus.
- Higher DNA G+C content in thermophilic Bacillus correlates with observed amino acid preferences, a factor not observed in Methanococcus.
Conclusions:
- Temperature-driven selection significantly shapes protein sequences, with distinct patterns observed even within closely related genera.
- Genomic factors, such as DNA G+C content, can influence or complicate temperature-adaptive amino acid substitutions.
- Comparative genomics provides a powerful approach to uncover taxon-specific evolutionary adaptations.
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