The deduced amino acid sequence of Mpr (A) and heteroprocessing and autoprocessing of Mpr in the extracellular milieu of B. subtilis (B). (A) Asterisks indicate the experimentally determined first amino acid residues of pro-Mpr and mature Mpr, respectively. Glutamic acid residues are underlined. (B) The initial translation product of the mpr transcript consists of a signal sequence (Pre; amino acids 1 to 34), a propeptide region (Pro; amino acids 35 to 93), and the mature enzyme (Mature; amino acids 94 to 313). Lined and dashed arrows indicate heteroprocessing by other extracellular proteases, and autoprocessing, respectively.