The type III protein translocation system of enteropathogenic Escherichia coli involves EspA-EspB protein interactions.

摘要: Enteropathogenic Escherichia coli (EPEC), like many bacterial pathogens, use a type III secretion system to deliver effector proteins across the cell wall. In EPEC, four proteins, EspA, EspB, EspD and Tir are known be exported by essential for 'attaching effacing' (A/E) lesion formation, hallmark of EPEC pathogenicity. EspA was recently shown structural protein major component large, transiently expressed, filamentous surface organelle which forms direct link between bacterium host cell. contrast, EspB is translocated into where it localized both membrane cytosolic fractions. required translocation suggesting that they may components apparatus. this study, we show co-immunoprecipitates with filaments that, during infection HEp-2 cells, localizes closely EspA. Using number binding assays, also can bind copurified Nevertheless, membranes occurred even in absence EspB. These results suggest following initial attachment target delivered interaction important translocation.