Novel Transcript Truncating Function of Rap1p Revealed by Synthetic Codon-Optimized Ty1 Retrotransposon

Extensive mutagenesis via massive recoding of retrotransposon Ty1 produced a synthetic codon-optimized retrotransposon (CO-Ty1). CO-Ty1 is defective for retrotransposition, suggesting a sequence capable of down-regulating retrotransposition. We mapped this sequence to a critical ∼20-bp region within CO-Ty1 reverse transcriptase (RT) and confirmed that it reduced Ty1 transposition, protein, and RNA levels. Repression was not Ty1 specific; when...