Amino Acid Properties, Substitution Rates, and the Nearly Neutral Theory.

ABSTRACT: Do the properties of amino acids affect their rates of substitution? The neutral theory predicts that greater selective constraint leads to slower rates of evolution; similarly, we expect amino acids that are more different from each other to have lower rates of exchange because such changes are most likely to affect protein structure and function. Here, we test these predictions, using substitution rates estimated from empirical amino acid exchangeability matrices. To measure degree of amino acid difference, we focused on two physicochemical properties, charge and size, uncorrelated metrics that are known to have important implications for protein structure and function. We find that for both charge and size, amino acid pairs with large differences had lower rates of substitution. We also

SUBMITTER: James JE 

PROVIDER: S-EPMC11884779 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature