Summary of the effects of Hsp70 and various phospholipids on the TBSV p92-Δ167N RdRp activities. Summary of the effects of Hsp70 and various phospholipids on the TBSV p92-Δ167N RdRp activities. We propose that the p92-Δ167N RdRp protein becomes activated in the presence of Hsp70, PE, or PC and the viral (+)RNA carrying the p33RE cis-acting sequence. These components facilitate the 3-TEX activity of p92-Δ167N RdRp in vitro. If the p33 replication protein and cellular membrane are also present in the assay (see the area within the dotted box), then p92-Δ167N RdRp could initiate de novo and produce full-length complementary product (41). If PG or, to a lesser extent, CA binds to the p92-Δ167N RdRp, then the (+)RNA binding by the RdRp is inhibited, thus blocking the RdRp activation step. Note that the activation of the full-length p92 RdRp (bottom part) is more complex, requiring additional components, such as the p33 replication cofactor and subcellular membranes and additional cis-acting elements (SL3+SL1 within the 3′-untranslated region) present in the viral (+)RNA (41). Judit Pogany, and Peter D. Nagy J. Virol. 2015;89:5714-5723