1.W.5. The (Lambda) Phage Portal Protein 5 (PPP5) Family
The Escherichia phage lambda (Bacteriophage lambda) portal protein forms the portal vertex of the capsid (Kochan and Murialdo 1983). This portal plays critical roles in head assembly, genome packaging, neck/tail attachment, and genome ejection. The portal protein multimerizes as a single ring-shaped homododecamer arranged around a central channel (Kochan et al. 1984). It binds to the terminase subunits to form the packaging machine (Yeo and Feiss 1995).