substrate specificity. Purified recombinant SrtBΔN26 protein was incubated with a range of peptide sequences to investigate its substrate specificity. The motifs SPKTG, PPKTG, SPSTG and SPQTG were all recognized and cleaved following incubation with SrtBΔN26. The scrambled peptide sequences GSKTP, GPKTG, GSSTP, and GSQTP serve as controls for the cleavage specificity of SrtBΔN26. The sequences LPETG and NPQTN, corresponding to the motifs recognized by S. aureus sortase A and B, respectively, do not appear to be substrates for SrtBΔN26. SrtBΔN26 also failed to cleave the proposed sorting signal NVQTG from recently characterized collagen binding protein, CbpA. Bars indicate the mean, and error bars represent the standard error (**corresponds to p < 0.01).