Arginine decarboxylase (EC:4.1.1.19) catalyses the interconversion of arginine and agmatine plus carbon dioxide [1]. It requires a pyruvoyl group for its activity. Archaeoglobus fulgidus contains three copies of this 80-residue domain, all of which are very closely related.
Tolbert WD, Graham DE, White RH, Ealick SE.
Pyruvoyl-dependent arginine decarboxylase from Methanococcus jannaschii: crystal structures of the self-cleaved and S53A proenzyme forms.
Structure 11 285-94 2003
[PubMed: 12623016] http://dx.doi.org/10.1016/S0969-2126(03)00026-1