Index >> Bacteriophages - Part One >> Prohead I - 400S of Phage T4

Prohead I - 400S of Phage T4 -

The earliest stage of head formation is a 'core' composed of gp22 and gpIPIII. It is formed in association with the cell membrane: Surrounding the core is the capsid, of which the main structural protein is gp23. It is activated by gp31.

The cleavage of gp22 is brought about mainly by gp22 and possibly also bygp2L -gp2.2 determines the short diameter of the prolate icosahedral capsid, white gp20 determines the long diameter gp42 ultimately digests itself into small peptides. The formation of prohead I requites gp3Iand gp40.