PgaPase_1 is a family of functionally diverse Caenorhabditis proteins. The family is homologous to the cysteine-peptidases, but lack of a strictly conserved Glu-Cys-His catalytic triad or pGlu binding site implies that it has other functions that could have resulted in a change in reaction-specificity or even of catalytic activity [1].

1: The challenge of annotating protein sequences: The tale of eight domains of unknown function in Pfam. Goonesekere NC, Shipely K, O'Connor K; Comput Biol Chem. 2010;34:210-214. PMID:20537955