Fig. 3.
UVDE, which incises the phosphodiester backbone 5′ to the 6-4 PP, quadruple nucleotide flips the covalently linked base damage and the two nucleotides opposite. A) Side and B) top views of UVDE, inserts a wedge (Gln103 and Tyr104), as it double flips two nucleotides on both strands. C) Schematic of DNA and relative position of wedge residues. It is notable how accessible is the bound 6-4 PP.