Synthetic evolutionary origin of a proofreading reverse transcriptase

Abstract

Making error-free DNA from RNA: DNA polymerase enzymes copy DNA into new strands of identical DNA. Reverse transcriptase (RT) enzymes copy RNA into DNA. Unlike many DNA polymerases, RT enzymes do not have a proofreading function that checks for errors in the newly synthesized DNA. Ellefson et al. use in vitro directed evolution and protein engineering to build an error-correcting RT from a prokaryotic DNA polymerase. The RT “xenopolymerase” shows increased fidelity as compared to natural RTs and should streamline and increase the precision of transcriptomics methods. Science , this issue p. 1590