Abstract
In a previous study, we showed that MMLV-RT has a strong terminal transferase activity, and that the C-, G-, and T-tailing activities are enhanced by dGMP, dCMP, and dAMP, respectively. In this study, to achieve faster reaction and higher tailing efficiency, we screened other compounds for the ability to enhance the tailing activities of MMLV-RT, and determined the corresponding optimal concentrations. The C-, G-, and T-tailing activities were enhanced by guanine, cytosine, and adenine, respectively, and by derivatives thereof, suggesting a transient Watson-Click base pairing between an enhancer molecule and the nucleotide to be incorporated. In the presence of some additives (GMP and GDP for C-tailing and CMP for G-tailing), the tail length increased continuously, resulting in tail lengths of 7 to 15 (GMP and GDP) or 13 to 22 (CMP) nucleotides. Among the compounds that do not induce continuous addition, adenosine, deoxycytidine, and deoxyguanosine mostly enhanced T-, G-, and C-tailings, respectively. The enhancing chemicals described here will improve the feasibility of N-tailing by MMLV-RT in various biotechnological applications.