Co-expression of a retrotransposon and re-targeted restriction factor impairs yeast growth

Retrotransposons and retroviruses shape genome evolution and can negatively impact genome function. <i>Saccharomyces cerevisiae</i> minimizes replication of Ty1 family retrotransposons using an inhibitory protein identical to the C-terminal domain of the transposon's capsid protein. We previously elucidated the molecular basis of restriction and subfamily specific targeting and engineered a re-targeted restriction factor. Here, we report that co-expression of the Ty1' retrotransposon and a variant of its restriction factor mutated to re-target a related transposon subfamily impairs yeast growth.