Fig. 1

The M14 metallocarboxypeptidase family includes several predicted pseudopeptidases. a The amino acid sequences of two active M14 metallocarboxypeptidase enzymes, CPA1 and CPE, were aligned with the sequences of several predicted pseudoenzymes of the M14 family using Clustal Omega. The sequences of the carboxypeptidase domains only are shown. Amino acids considered critical active site residues within M14 carboxypeptidases are shown in red, with the corresponding numbering from mature bovine CPA1 shown above. Blue background shading indicates increasing levels of sequence conservation from light to dark. Numbers on left and right indicate amino acid number within the complete protein. b A three-dimensional model for S. cerevisiae Ecm14, with the prodomain shown in blue and the carboxypeptidase-like domain shown in green. A coordinated zinc is modeled as a red sphere, and the arginine at which a tryptic-like enzyme may cleave is shown in stick representation. c The active site of bovine CPA1 is compared with the corresponding amino acids within S. cerevisiae Ecm14 (d)