Selective base-pair destabilization enhances binding of a DNA methyltransferase

Abstract

Disulfide crosslinks were introduced into the minor groove of DNA using the convertible nucleoside approach. Depending upon the length of the tether, the modified base pairs were either stabilized or destabilized. When the base-pairs were destabilized, the oligonucleotide was bound by a DNA (cytosine-5)-methyltransferase (DCMtase) about 50-fold more tightly than the corresponding unmodified oligonucleotide. Insights into the mechanism of DCMtases are discussed.