Transferase enzymes which modify the 3'-termini of ribonucleic acid and methods

Abstract

Three ribonucleotidyl terminal transferase enzymes are disclosed which modify the 3'-termini of ribonucleic acid (RNA) molecules by the addition of ribonucleotide units using ribonucleoside triphosphates as substrates. These terminal transferase activities are distinguishable by the specific ribonucleotide (e.g. AMP, CMP, or UMP) transferred to the 3'-hydroxyl terminus of an RNA primer. Also provided is a method for the 3'-terminal modification of RNA molecules by these enzymes and sequencing of RNA from its 3'-termini. The methods provide a convenient and efficient procedure for 3'-terminal modification (homopolymer tailing) of RNA required for synthesis of complete complementary DNA (cDNA) copies or double-stranded DNA gene copies by retrovirus-associated reverse transcriptase. Using the enzymes of the invention, RNA can also be radiolabelled to very high levels for molecular hybridization.

Dependencies are inferred from the claim text.