- The SapB morphogen is a lantibiotic-like peptide derived from the product of the developmental gene ramS in Streptomyces coelicolor. Kodani, S., Hudson, M.E., Durrant, M.C., Buttner, M.J., Nodwell, J.R., Willey, J.M. Proc. Natl. Acad. Sci. U.S.A. (2004)