A pilot protein participates in the initiation of P22 procapsid assembly

Academic Article


  • The gene 16 protein of the bacteriophage P22 is required as a pilot protein aiding the transfer of DNA from the phage into the Salmonella typhimurium host cell. During assembly 10-20 copies of the 63,000-Da gpl6 protein are incorporated into the procapsid shell prior to DNA packaging. The protein has been purified from isolated procapsids and behaved as a monomer in solution. Upon incubation with purified coat and scaffolding subunits in vitro, it assembled into procapsids with the correct stoichiometry. The addition of physiological quantities of gpl6 resulted in an increased rate of procapsid assembly. Sedimentation of mixtures of coat and gp16 protein subunits revealed association/dissociation behavior. It is likely that the added gp16 is acting to stabilize a transient oligomeric coat protein species that functions as the in vitro initiation complex for procapsid assembly. © 1991.
  • Published In

  • Virology  Journal
  • Digital Object Identifier (doi)

    Author List

  • Thomas D; Prevelige P
  • Start Page

  • 673
  • End Page

  • 681
  • Volume

  • 182
  • Issue

  • 2