Synonymous mutations make dramatic contributions to fitness when growth is limited by a weak-link enzyme.

ABSTRACT: Synonymous mutations do not alter the specified amino acid but may alter the structure or function of an mRNA in ways that impact fitness. There are few examples in the literature, however, in which the effects of synonymous mutations on microbial growth rates have been measured, and even fewer for which the underlying mechanism is understood. We evolved four populations of a strain of Salmonella enterica in which a promiscuous enzyme has been recruited to replace an essential enzyme. A previously identified point mutation increases the enzyme's ability to catalyze the newly needed reaction (required for arginine biosynthesis) but decreases its ability to catalyze its native reaction (required for proline biosynthesis). The poor performance of this enzyme limits growth rate on glucose. Aft

SUBMITTER: Kristofich J 

PROVIDER: S-EPMC6128649 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature