ALKBH6 binds with different types of DNAs.A, ALKBH6 and mutants interact with FAM-ssDNA1. R68A and R74A mutants almost completely abolished the ssDNA binding ability, whereas the R225A/R228A mutant was comparable with the wildtype. Proposed model of ALKBH6 binding with single-stranded (B) or bubble nucleic acid (C), the key residues for binding are circled in yellow and labeled. D, ALKBH6ΔFlip3 binds with dsDNA. CKΔFlip3, only ALKBH6ΔFlip3 protein; CKN, only nucleic acid.