Crystal structure of Lactobacillus species 30a Histidine Decarboxylase (pyruvoyl-dependent) has been determined to 2.5 Å resolution by T. Gallagher, D.A.Rozwarski, S.R. Ernst, M.L. Hackert
J. Mol. Biol. (1993) 230, 516.
PDB code 1PYA.

The protein is a trimer of dimers: beta subunit (residues 1-81; red) and alpha subunit (82-310; green). It is produced as inactive polypeptide 1-310. During self-activation bond between Ser81 and Ser82 is cleaved and Ser82 is transformed into pyruvoyl moiety.