Assembly and mechanisms of bacterial type IV secretion machines

摘要: Type IV secretion occurs across a wide range of prokaryotic cell envelopes: Gram-negative, Gram-positive, wall-less bacteria and some archaea. This diversity is reflected in the heterogeneity components that constitute machines. Macromolecules are secreted an ATP-dependent process using envelope-spanning multi-protein channel. Similar to type III systems, this apparatus extends beyond surface as pilus structure important for direct contact penetration recipient surface. systems remarkably versatile they mobilize broad substrates, including single proteins, protein complexes, DNA nucleoprotein envelope. These machines have clinical significance not only delivering bacterial toxins or effector proteins directly into targeted host cells, but also involvement phenomena such biofilm formation rapid horizontal spread antibiotic resistance genes among microbial community.