大肠杆菌的蛋白分泌机制

大肠杆菌的分泌蛋白定位于内膜、外膜、周质空间和胞外环境,它们在N端或C端带有一定的结构包含着分泌信号,这两类分泌蛋白在各自特定的一组蛋白因子的协助下跨越内膜,再通过目前尚不清楚的方式实现其最终定位.N端带有信号肽的分子在跨越内膜时得到Sec家族蛋白因子协助,信号肽在跨膜过程中可能被切除,该过程由ATP和电化学势提供能量.C端带分泌信号的分子主要受到Hly家族分子协助,一次穿过内膜和外膜而不经过周质空间.

The Mechanism of Protein Secretion in E.coli

Secretive proteins in E.coli, which are located in the inner membrane,the outer membrane,the periplasmic space or the environment,have a structure containing the secretion signal on the N or C terminal.These two sorts of proteins elbow through the inner membrane with the help of two series of distinguishable protein factors and realize their final position by an unelucidated mechanism. The molecule containing its signal peptide on the N terminal is assisted by protein factors of the Sec family when rushing through the cytoplasma membrane. The leading peptide might be cut off in the process. ATP and the electrical potential supply the energy for the secretion. The molecule which has secretion signal on its C terminal is helped by the Hly family members to pass the inner and outer membrave at the same time while omitting the periplasmic space.