Evolution of Amino Acid Propensities under Stability-Mediated Epistasis.

ABSTRACT: Site-specific amino acid preferences are influenced by the genetic background of the protein. The preferences for resident amino acids are expected to, on average, increase over time because of replacements at other sites-a nonadaptive phenomenon referred to as the "evolutionary Stokes shift." Alternatively, decreases in resident amino acid propensity have recently been viewed as evidence of adaptations to external environmental changes. Using population genetics theory and thermodynamic stability constraints, we show that nonadaptive evolution can lead to both positive and negative shifts in propensities following the fixation of an amino acid, emphasizing that the detection of negative shifts is not conclusive evidence of adaptation. By examining propensity shifts from when an amino acid

SUBMITTER: Youssef N 

PROVIDER: S-EPMC8896634 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature