Models for the role Cpr7p in tombusvirus replication.

<p>Model 1: Cpr7p has been shown to inhibit the recruitment of the viral RNA into replication. Model 2: The assembly of the tombusviral VRC requires interactions among the viral replication proteins, selected host proteins, such as Hsp70, GAPDH or eEF1A or membrane lipids. Cpr7p might inhibit any of these interactions, resulting in reduced TBSV RNA replication. In addition, Cpr7p binds to the RPR RNA binding motif in p33 and likely inhibiting p33: viral (+)RNA interaction that is needed for VRC assembly. Model 3: Due to the chaperone activity of the TPR domain, binding of Cpr7p to p92 might inhibit the RdRp function of p92, thus blocking RNA synthesis. See further details in the text.