Site-Specific Amino Acid Preferences Are Mostly Conserved in Two Closely Related Protein Homologs.

ABSTRACT: Evolution drives changes in a protein's sequence over time. The extent to which these changes in sequence lead to shifts in the underlying preference for each amino acid at each site is an important question with implications for comparative sequence-analysis methods, such as molecular phylogenetics. To quantify the extent that site-specific amino acid preferences shift during evolution, we performed deep mutational scanning on two homologs of human influenza nucleoprotein with 94% amino acid identity. We found that only a modest fraction of sites exhibited shifts in amino acid preferences that exceeded the noise in our experiments. Furthermore, even among sites that did exhibit detectable shifts, the magnitude tended to be small relative to differences between nonhomologous proteins. Give

SUBMITTER: Doud MB 

PROVIDER: S-EPMC4626756 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature