Histidine decarboxylase from Lactobacillus 30a was the first pyruvoyl-dependent enzyme reported.  Rather than being a vitamin B6 (PLP)-dependent decarboxylase, this protein makes its own prosthetic group by converting an internal serine residue in its proenzyme form into a pyruvoyl group that promotes the decarboxylation of histidine into histamine  (PDB 1PYA).