This model describes a subfamily of MEROPS peptidase family M42, a glutamyl aminopeptidase family that also includes the cellulase CelM from Clostridium thermocellum and deblocking aminopeptidases that can remove acylated amino acids. Members of this family occur in a three gene cassette with an amidotransferase (TIGR03104)in the asparagine synthase (glutamine-hydrolyzing) family, and a probable acetyltransferase (TIGR03103) in the GNAT family.