Читать книгу Snyder and Champness Molecular Genetics of Bacteria - Tina M. Henkin - Страница 237

Pathogenic bacteria that lack the secretion systems described above require alternative mechanisms to translocate virulence effectors into eukaryotic cells. Some AB-type toxins, such as diphtheria toxin, and clostridial neurotoxins, such as botulinum toxin, are self-translocating, similar to the autotransporter systems described above. However, some bacteria, such as Streptococcus pyogenes, inject a virulence effector into the mammalian target cell by a mechanism functionally analogous to the T3SS (see Madden et al., Suggested Reading). This has been named an injectosome to distinguish it from the standard type III injectisome (note the different spellings). As shown in Figure 2.41, the function of the injectosome requires cotranslational translocation of the effector by the Sec-dependent secretion system across the bacterial membrane before it translocates the effector through the cell wall and directly across the membrane of the eukaryotic target cell.