Unprecedented dinuclear silver(I)-mediated base pair involving the DNA lesion 1,N6-ethenoadenine

The DNA lesion 1, N-6-ethenoadenine (epsilon A) has been investigated with respect to its metal-binding properties. A synthetic DNA duplex comprising an eA : eA mispair readily forms doubly silver(I)mediated base pairs epsilon A-Ag(I)(2)-epsilon A, representing the first example for a dinuclear metal-mediated homo base pair of a purine derivative. It also constitutes the first example for a Hoogsteen-type metal-mediated homo base pair within a B-DNA duplex.