*1.W.6. The (Bacillus* Phage phi29) Portal Protein 6 (PPP6) Family** The phage phi29 portal protein forms the portal vertex of the capsid (Ibarra et al. 2000; Fu and Prevelige 2009; Grimes et al. 2011). 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 (Guasch et al. 2002; Grimes et al. 2011). It binds to the 6 packaging RNA molecules (pRNA) forming a double-ring structure which in turn binds to the ATPase gp16 hexamer, forming the active DNA-translocating motor (Xiao et al. 2005; Simpson et al. 2000). This complex is essential for the specificity of packaging from the left DNA end. Thus, it is involved in viral genome ejection through the host cell envelope and penetration into the host cytoplasm.
References:
Fu, C.Y. and P.E. Prevelige, Jr. (2009). In vitro incorporation of the phage Phi29 connector complex. Virology 394: 149-153.
Grimes, S., S. Ma, J. Gao, R. Atz, and P.J. Jardine. (2011). Role of φ29 connector channel loops in late-stage DNA packaging. J. Mol. Biol. 410: 50-59.
Guasch, A., J. Pous, B. Ibarra, F.X. Gomis-Rüth, J.M. Valpuesta, N. Sousa, J.L. Carrascosa, and M. Coll. (2002). Detailed architecture of a DNA translocating machine: the high-resolution structure of the bacteriophage φ29 connector particle. J. Mol. Biol. 315: 663-676.
Ibarra, B., J.R. Castón, O. Llorca, M. Valle, J.M. Valpuesta, and J.L. Carrascosa. (2000). Topology of the components of the DNA packaging machinery in the phage φ29 prohead. J. Mol. Biol. 298: 807-815.
Simpson, A.A., Y. Tao, P.G. Leiman, M.O. Badasso, Y. He, P.J. Jardine, N.H. Olson, M.C. Morais, S. Grimes, D.L. Anderson, T.S. Baker, and M.G. Rossmann. (2000). Structure of the bacteriophage φ29 DNA packaging motor. Nature 408: 745-750.
Xiao, F., W.D. Moll, S. Guo, and P. Guo. (2005). Binding of pRNA to the N-terminal 14 amino acids of connector protein of bacteriophage φ29. Nucleic Acids Res 33: 2640-2649.
Examples:
TC#	Name	Organismal Type	Example
1.W.6.1.1	The Bacillus phage phi29 (φ29) portal protein of 309 aas. It forms the portal vertex of the capsid (Ibarra et al. 2000; Fu and Prevelige 2009; Grimes et al. 2011). This portal plays 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 (Guasch et al. 2002, Grimes et al. 2011). It binds to the 6 packaging RNA molecules (pRNA), forming a double-ring structure which in turn binds to the ATPase gp16 hexamer, forming the active DNA-translocating motor (Xiao et al. 2005, Simpson et al. 2000). This complex is essential for the specificity of packaging from the left DNA end.		*PPP of Bacillus* phage phi29**

1.W.6.1.2	Uncharacterized protein of 358 aas		UP of Candidatus Melainabacteria bacterium (human gut metagenome)

1.W.6.1.3	Capsid and scaffold protein of 344 aa		Capsid protein of Enterococcus phage vB_EfaP_Efmus1

Examples:
TC#	Name	Organismal Type	Example
1.W.6.2.1	Uncharacterized protein of 309 aas		UP of endosymbiont GvMRE

1.W.6.2.2	Uncharacterized protein of 310 aas		UP of endosymbiont GvMRE of Glomus versiforme

Examples:
TC#	Name	Organismal Type	Example
1.W.6.3.1	Uncharacterized protein of 334 aas		UP of Mycoplasmataceae bacterium CE_OT135 (symbiont metagenome)

1.W.6.3.2	Uncharacterized protein of 306 aas		UP of endosymbiont DhMRE of Dentiscutata heterogama

1.W.6.3.3	Uncharacterized protein of 275 aas		UP of Terfezia boudieri

Examples:
TC#	Name	Organismal Type	Example
1.W.6.4.1	Uncharacterized protein of 700 aas		UP of Pseudogymnoascus verrucosus

1.W.6.4.2	Uncharacterized protein of 643 aas		UP of Kalmanozyma brasiliensis