Binding of YopM-InlB to MET. (A) Elution profiles from gel filtration are shown for the complete MET ectodomain, for wild type InlB321, for YopM-InlB and the respective complexes. Wild type InlB321 is quantitatively shifted into a complex with MET eluting earlier than the isolated MET ectodomain. In contrast, the elution volume of YopM-InlB is only slightly shifted and its peak shows fronting indicating low affinity binding to MET, the elution behaviour of which is virtually unchanged. (B) Solid-phase binding assay, in which the complete MET ectodomain (MET928) was immobilized on ELISA plates and incubated with increasing concentrations of GST-tagged InlB321 and GST-tagged YopM-InlB. Binding was detected with a horseradish peroxidase-coupled anti-GST antibody. Three independent experiments, in which each protein was tested in triplicate, were normalized and then averaged. Error bars show standard deviation.