This region is found in plant seed storage proteins, N-terminal to the Cupin domain (Pfam:PF00190). In Macadamia integrifolia (Swiss:Q9SPL4), this region is processed into peptides of approximately 50 amino acids containing a C-X-X-X-C-(10-12)X-C-X-X-X-C motif. These peptides exhibit antimicrobial activity in vitro [1].

1: A family of antimicrobial peptides is produced by processing of a 7S globulin protein in Macadamia integrifolia kernels. Marcus JP, Green JL, Goulter KC, Manners JM; Plant J 1999;19:699-710. PMID:10571855