This family is based on the third domain of the PDB structure 3KD4(residues 410-525). It is structurally similar to part of neuropilin-2 (Z=4.6, rmsd 3.6A for 83 CA, 7% seq id). This domain and the second domain appears to be part of peptide-n-glycanase (1x3w, 2g9f).