Читать книгу Snyder and Champness Molecular Genetics of Bacteria - Tina M. Henkin - Страница 223

The Tat system of E. coli has three subunits, TatA, TatB, and TatC, while that of B. subtilis has only two, with TatA and TatB seemingly combined into one larger subunit. In E. coli, TatB and TatC bind the signal peptide on the protein to be transported and then recruit TatA, which forms the channel in the membranes. In this way, the channel may form only when there is a protein to be transported. Unlike the Sec translocon, which uses both the energy of ATP cleavage by SecA and the proton motor force to drive the protein through the channel, the Tat system may use only the latter.