GCNA, Spartan, and Wss1 form a subgroup within the larger Peptidase Clan MA.

Clan MA, one of 15 clans of metallopeptidases in MEROPS, contains all of the peptidases that have arisen from a single evolutionary origin as defined by tertiary structure, the order of catalytic residues, and sequence motifs surrounding the catalytic site. Dendrogram was constructed by heirarchically clustering protein groups based on comparison of HMMs using alignment and secondary structure scoring.