Roles of the Y-family DNA polymerase Dbh in accurate replication of the Sulfolobus genome at high temperature

► Dbh is the Y-family trans-lesion DNA polymerase of Sulfolobus acidocaldarius. ► Crystal structures of this polymerase provide valuable information on TLS. ► To analyze its biological function, the S. acidocaldarius dbh gene was disrupted. ► The phenotype of disruptants indicates both mutagenic and anti-mutagenic roles.