Crystal Structure of a Y-family DNA Polymerase in a Ternary Complex with DNA Substrates and an Incoming Nucleotide Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) is a DinB homolog that belongs to the recently described Y-family of DNA polymerases, which are best characterized by their low-fidelity synthesis on undamaged DNA templates and propensity to traverse normally replication-blocking lesions. By Bathsheba Bathsheba — DNA polymerase Bathsheba—DNA—polymerase