Differential solvation and tautomer stability of a model base pair within the minor and major grooves of DNA.

摘要: 2-(2'-Hydroxyphenyl)benzoxazole (HBO) may be used as a model base pair to study solvation, duplex environment, and tautomerization within the major minor groves of DNA duplexes. In its ground state, HBO possesses an enol moiety which oriented syn or anti relative imino nitrogen benzoxazole ring. absence external hydrogen-bond donors acceptors exists internally hydrogen-bonded syn-enol, mimic rare tautomer found in DNA, photoinduced tautomerize form keto tautomer, dominant tautomer. Previously, we demonstrated that when incorporated into such is positioned groove, not solvated, exclusively syn-enol efficiently tautomerize, corresponding preferentially stabilized. stark contrast, now show Molecular dynamics simulations suggest this results from formation stable between O4' atom adjacent nucleotide, H-bond acceptor only available groove. The differential stabilization tautomers grooves reflect functions for these environments evolved, including replication, stability, recognition.