Stepwise expansion of the bacteriophage ϕ6 procapsid: possible packaging intermediates.

ABSTRACT: The initial assembly product of bacteriophage ϕ6, the procapsid, undergoes major structural transformation during the sequential packaging of its three segments of single-stranded RNA. The procapsid, a compact icosahedrally symmetric particle with deeply recessed vertices, expands to the spherical mature capsid, increasing the volume available to accommodate the genome by 2.5-fold. It has been proposed that expansion and packaging are linked, with each stage in expansion presenting a binding site for a particular RNA segment. To investigate procapsid transformability, we induced expansion by acidification, heating, and elevated salt concentration. Cryo-electron microscopy reconstructions after all three treatments yielded the same partially expanded particle. Analysis by cryo-electron tomo

SUBMITTER: Nemecek D 

PROVIDER: S-EPMC3223026 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature