FIG 4.

The coat protein D14A mutant is highly defective in scaffolding protein binding. (A) Purified procapsids with the D14A, E15A, or E18A coat protein run on 10% SDS-PAGE gels to analyze protein content. WT procapsids generated from coexpression of coat and scaffolding proteins from the pET3a plasmid and WT procapsids from 2⁻ 13⁻ phage-infected cells are shown as controls. The migration of coat protein is indicated by “c,” and the migration of scaffolding protein is indicated by “s.” (B to E) Electron micrographs of particles generated from WT (B) and D14A (C), E15A (D), and E18A (E) coat proteins, showing significantly aberrant structures for the D14A mutant but not for the other mutants. The bar represents 100 nm.