%0 Journal Article
%T Protein P7 of the Cystovirus ¦Õ6 Is Located at the Three-Fold Axis of the Unexpanded Procapsid
%A Garrett Katz
%A Hui Wei
%A Alexandra Alimova
%A Al Katz
%A David Gene Morgan
%A Paul Gottlieb
%J PLOS ONE
%D 2012
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0047489
%X The objective of this study was to determine the location of protein P7, the RNA packaging factor, in the procapsid of the ¦Õ6 cystovirus. A comparison of cryo-electron microscopy high-resolution single particle reconstructions of the ¦Õ6 complete unexpanded procapsid, the protein P2-minus procapsid (P2 is the RNA directed RNA-polymerase), and the P7-minus procapsid, show that prior to RNA packaging the P7 protein is located near the three-fold axis of symmetry. Difference maps highlight the precise position of P7 and demonstrate that in P7-minus particles the P2 proteins are less localized with reduced densities at the three-fold axes. We propose that P7 performs the mechanical function of stabilizing P2 on the inner protein P1 shell which ensures that entering viral single-stranded RNA is replicated.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0047489