Proteolytic digests of putative substrate proteins. (A) Recombinant substrate proteins were digested with each of the four proteinases. -: neg. control, Sc: S. cerevisiae Kex2, Ca: C. albicans Kex2, Cg: C. glabrata Kex2 and Pp: P. pastoris Kex2. Potential fragment sizes are given in kDa underneath the names (vertical bars: potential cleavage sites). All digests were visualized in silver stained gels, except CaSun41, where the N-terminal X-press epitope was detected in a Western blot. Proteins are digested at all major substrate sites found in the sequence and for most, intermediate products can be observed. Proteins not hydrolysed by Kex2 are not depicted (see text). Substrate CA0365 is not processed by ScKex2, but by all other proteinases, most efficiently by CaKex2.