1.W.9. The Escherichia coli Mu Phage Portal Protein 9 (PPP9) Family
The phage Mu protein forms the portal vertex of the capsid (Grimaud 1996). 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 (Grimaud and Toussaint 1998). and binds to the terminase subunits to form the packaging machine. It also acts as a
linker between the capsid and tail and is required for attachment of the neck
proteins to the capsid. The viral genome is injected through the host cell envelope using a cntractile tail mechanism (Morgan et al. 2002).
This family belongs to the: Phage Portal Protein (PPP) Superfamily.
References associated with 1.W.9 family:
Grimaud, R. (1996). Bacteriophage Mu head assembly. Virology 217: 200-210. 8599204
Grimaud, R. and A. Toussaint. (1998). Assembly of both the head and tail of bacteriophage Mu is blocked in Escherichia coli groEL and groES mutants. J. Bacteriol. 180: 1148-1153. 9495752
Morgan, G.J., G.F. Hatfull, S. Casjens, and R.W. Hendrix. (2002). Bacteriophage Mu genome sequence: analysis and comparison with Mu-like prophages in Haemophilus, Neisseria and Deinococcus. J. Mol. Biol. 317: 337-359. 11922669