<p>Polyadenylation assays were performed with radiolabeled unmodified (A and C) and native (B and D) tRNA<sub>i</sub><sup>Met</sup> substrate incubated with 25, 50, or 100 ng of Trf4-TAP complex (Trf4-TAP; A and B), or with 5, 10, or 20 ng of recombinant Trf4 protein expressed in the baculovirus system (Trf4-bac; A and B), or with 5, 10, or 20 ng of mutant Trf4-bac (DADA-bac; C and D), or with equal amounts and dilutions of control eluates (CTRL-bac; proteins from cell lysates that unspecifically bound to the Ni<sup>2+</sup>-NTA matrix; C and D). In reconstitution experiments 20 ng of Trf4-bac, or DADA-bac, or control eluates were mixed with 0.5, 3, or 15 ng of recombinant Air1p and/or recombinant Air2p in the combinations indicated. The proteins were pre-incubated for 30 min on ice to allow for binding. Reactions were incubated for 50 min at 30 °C. Control reactions contained no protein (lane 1 in each gel).</p
