Synthesis of the analogue nucleoside 3-deaza-2 '-deoxycytidine and its template activity with DNA polymerase

A new synthesis of the nucleoside analogue 3-deaza-2'-deoxycytidine is desc ribed. The N-3-nitrogen of dC is involved in the central hydrogen bond of a dG-dC base pair. The relative importance of hydrogen bonding as a controll ing factor in the activity of DNA polymerase is examined by studying both d uplex stability and template effects for this dc(3)C nucleoside. Duplexes c ontaining dG-dc(3)C base pairs were strongly destabilized while templates c ontaining the analogue nucleoside were found to incorporate only the comple mentary dG triphosphate, similar to observations with templates containing the native 2'-deoxycytidine. (C) 1999 Elsevier Science Ltd. All rights rese rved.