DNA polymerases are used in a plethora of biotechnical applications, especially in the polymerase chain reaction (PCR), genetic cloning procedures, genome sequencing, and diagnostic methods.[1] Highly processive and accurate DNA polymerases are desired for cloning procedures in order to give shorter extension times as well as more robust and highyield amplification. A higher DNA polymerase fidelity may increase the reliability of genome sequencing and diagnostic systems.[2] Amplification of ancient DNA samples requires DNA polymerases with an increased substrate spectrum to efficiently overcome typical DNA lesions.[3] To enhance the efficiency of forensic DNA testing, DNA polymerases resistant to inhibitors from blood and soil allow PCR without prior DNA purification.[4] Further improvements of DNA polymerases are required, for example, to meet the requirements of real-time DNA single-molecule sequencing, which relies on the ability ofDNApolymerases to efficiently process modified nucleotides.[5] Overall, customized and artificially engineered DNA polymerases that lead to more robust and specific reaction systems are urgently needed
