Adenine base at N7 position

The adenine base at the N7 position is a nitrogen atom located at the seventh position on the purine ring of adenine. This site plays a significant role in both chemical reactivity and molecular recognition within nucleic acids. It is a potential hydrogen bond acceptor and a target for metal ion coordination, particularly by platinum-based drugs. Modifications at this position can alter base stacking interactions, hydration patterns, and overall duplex stability without affecting Watson–Crick base pairing. It is not directly involved in Watson-Crick base pairing, but interacts with proteins and small molecules in the major groove.

Coordination to N7 position, forming adducts and disrupting DNA/RNA structure.