Structure and sequence at an RNA template 5′ end influence insertion of transgenes by an R2 retrotransposon protein

Model of RNA template 5′ module influence on PRINT efficiency and precision. (A) An RNA template with high biostability, imbued by a 5′ Rz structure with high thermodynamic stability or, more effectively, by synthesis with a stabilizing U analog, generates more productive insertions. RNA template instability correlates with more 5′-truncated insertions. (B) Separately from the 5′ module influence on RNA template biostability, the presence of 5′ homology with rRNA directs the mechanism of transgene 5′ junction formation as either Anneal or Join. Joins may occur with or without a microhomology signature.