Identification of additional coat-scaffolding interactions in a bacteriophage P22 mutant defective in maturation

Scaffolding proteins play a critical role in the assembly of certain viruse s by directing the formation and maturation of a precursor capsid, Using el ectron cryomicroscopy difference mapping, we have identified an altered arr angement of a mutant scaffolding within the bacteriophage P22 procapsid. Th is mutant scaffolding allows us to directly visualize scaffolding density w ithin the P22 procapsid, Based on these observations we propose a model for why the mutant prevents scaffolding release and capsid maturation.