Archaeal replicative primases can perform translesion DNA synthesis

DNA replicases stall at lesions during replication, potentially leading to genome instability. However, cells use specialized lesion bypass polymerases to restart stalled replisomes. Although most organisms possess these damage tolerance polymerases, capable of traversing blocking DNA lesions, many appear to lack these enzymes. We have discovered that replicative primases from archaea, previously considered to be solely involved in priming replication, are also capable of performing translesion DNA synthesis. This discovery has major implications for our understanding of additional roles of DNA primases during replication and the subsequent evolution of related lesion bypass pathways in eukaryotic organisms.