gp15 Protein, Escherichia phage T7 (His, StrepⅡ)

Gp15, a pivotal component of the cylindrical core, plays a crucial role in the assembly of the inner surface of the capsid during capsid formation and is actively involved in the ejection of viral DNA into the host cell. This inner core comprises stacked rings of gp14, gp15, and gp16 proteins. Upon binding to the host cell surface, the internal core undergoes disassembly, leading to the ejection of gp15, along with gp14 and gp16, into the infected cell. It is likely that gp15 remains associated with gp16. The resulting gp15-gp16 complex forms interactions with both the viral DNA and the host inner membrane, potentially guiding the leading end of the genome through the periplasm and regulating the extent of DNA translocated into the host cell. Gp15 functions as a homooctamer and interacts with gp16, forming a complex after ejection, composed of a gp15 octamer and a gp16 tetramer, which likely binds both the viral DNA and the host inner membrane. Furthermore, gp15 interacts with gp14, emphasizing its integral role in the intricate orchestration of events during the viral life cycle.