Figure 6.

Cartoons for dsDNA conformations in the presence and absence of bound AlkB or ABH2. a 1-meA may adopt an intrahelical configuration in double helix by forming a Hoogsteen type base paring with thymine from the complementary strand. b Escherichia coli AlkB squeezes dsDNA and induces severe distortion of the DNA duplex to facilitate base flipping. c ABH2 is a standard dsDNA damage repair protein that uses a finger residue (Phe102) to stabilizes the duplex structure after base flipping. d A close view of the structure of how AlkB binds dsDNA. e A close view of how ABH2 binds dsDNA