Cryo-electron tomography of bacteriophage phi6 procapsids shows random occupancy of the binding sites for RNA polymerase and packaging NTPase.

ABSTRACT: Assembly of dsRNA bacteriophage phi6 involves packaging of the three mRNA strands of the segmented genome into the procapsid, an icosahedrally symmetric particle with recessed vertices. The hexameric packaging NTPase (P4) overlies these vertices, and the monomeric RNA-dependent RNA polymerase (RdRP, P2) binds at sites inside the shell. P2 and P4 are present in substoichiometric amounts, raising the questions of whether they are recruited to the nascent procapsid in defined amounts and at specific locations, and whether they may co-localize to form RNA-processing assembly lines at one or more "special" vertices. We have used cryo-electron tomography to map both molecules on individual procapsids. The results show variable complements that accord with binomial distributions with means of 8 (

SUBMITTER: Nemecek D 

PROVIDER: S-EPMC2910799 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature