D. Warrilow et Rh. Symons, Citrus exocortis viroid RNA is associated with the largest subunit of RNA polymerase II in tomato in vivo, ARCH VIROL, 144(12), 1999, pp. 2367-2375
An active replication complex of citrus exocortis viroid (CEV) was isolated
as a chromatin-enriched fraction of infected tomato leaf with CEV RNA synt
hesis activity. This activity was solubilised from the chromatin with ammon
ium sulphate, but not with sarkosyl. Nucleoprotein complexes in the soluble
fraction which bound to a monoclonal antibody to the carboxy terminal doma
in of the largest subunit of RNA polymerase II (8WG16) were affinity purifi
ed and contained plus- and minus-sense CEV RNA. The results support a role
for RNA polymerase II in viroid replication and provide the first direct ev
idence of an association in vivo between host RNA polymerase II and CEV.