In Vitro Selection of Ligase Ribozymes Containing 2'-Amino Groups

Novel ribozymes containing 2'-amino groups in the side chains were in vitro selected to accelerate their ligation reaction rates with oligodeoxynucleotides. The ligation rate of random sequenced RNAs in the starting pool was accelerated by incorporation of 2'-amino-2'-deoxyuridine and N ⁶ -(6-aminohexyl)adenosine. The incorporation of the amino group enhanced the activity of non-selected RNAs independent of the incorporation site. In vitro selection using 2'-amino-2'-deoxyuridine instead of uridine produced more active ribozymes. In this case, the activity of ribozyme was reduced when N ⁶ -(6-aminohexyl)adenosine was incorporated into the selected RNAs instead of natural adenosine. The presence of amino groups as well as the incorporation site affected the activity of the in vitro selected ribozyme. It seems that RNAs with tertiary structures suitable for the ligation reaction were selected by the in vitro method.