YopB of Yersinia enterocolitica Is Essential for YopE Translocation

A previous study has shown that YopB of Yersinia spp. is essential for translocation of Yop effectors across the eucaryotic plasma membrane (M.-P. Sory and G. R. Cornelis, Mol. Microbiol. 14:583–594, 1994). However, this role was recently challenged (V. T. Lee and O. Schneewind, Mol. Microbiol. 31:1619–1629, 1999). Using protease protection and digitonin extraction, we reconfirm that YopB of Yersinia enterocolitica is essential for the translocation of YopE into HeLa cell monolayers.