In vitro association between the virulence proteins, YopD and YopE, of Yersinia enterocolitica.

Abstract

The virulence plasmid (pYV) of Y. enterocolitica encodes a set of anti-host proteins, known as Yops, which contribute to survival of the bacteria in the host. Several Yops directly influence the interaction of pathogenic bacteria with host cells which in the case of at least four Yops, YopE, YopH, YopM and YpkA (YopO), involves translocation of the Yop across the eukaryotic cell membrane into the cytoplasm of target cells. Translocation requires the presence of two other pYV-encoded proteins, YopB and YopD, but it is not clear how these proteins mediate translocation of the effector Yops. We have used an affinity blot technique (overlay) to examine potential binding between YopD and other Yops. The results indicated that under the in vitro conditions used in this study, YopD bound preferentially to YopE and YopB. To investigate the interaction of YopD and YopE in more detail we produced different regions of the YopD protein in Escherichia coli by creating fusions of YopD with glutathione S-transferase. These studies showed that YopE bound the central hydrophobic region of YopD. This is the first demonstration of protein interactions between an effector Yop and a putative Yop translocator.