Structural analysis of Bacillus pumilus phenolic acid decarboxylase, a lipocalin-fold enzyme.
The decarboxylation of phenolic acids, including ferulic and p-coumaric acids, to their corresponding vinyl derivatives is of importance in the flavouring and polymer industries. Here, the crystal structure of phenolic acid decarboxylase (PAD) from Bacillus pumilus strain UI-670 is reported. The enzyme is a 161-residue polypeptide that forms dimers both in the crystal and in solution. The structure of PAD as determined by X-ray crystallography revealed a β-barrel structure and two α-helices, with a cleft formed at one edge of the barrel. The PAD structure resembles those of the lipocalin-fold proteins, which often bind hydrophobic ligands. Superposition of structurally related proteins bound to their cognate ligands shows that they and PAD bind their ligands in a conserved location within the β-barrel. Analysis of the residue-conservation pattern for PAD-related sequences mapped onto the PAD structure reveals that the conservation mainly includes residues found within the hydrophobic core of the protein, defining a common lipocalin-like fold for this enzyme family. A narrow cleft containing several conserved amino acids was observed as a structural feature and a potential ligand-binding site.
Health Sector, Biotechnology Research Institute, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2, Canada.
Allan
A
Matte
Stephan
S
Grosse
Hélène
H
Bergeron
Kofi
K
Abokitse
Peter C K
PC
Lau
D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology*; D002262:Carboxy-Lyases / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
D002262:Carboxy-Lyases; C417714:phenolic acid decarboxylase