Molecular Characterization of the Poly(3‐hydroxybutyrate) Depolymerase Gene from Penicillium funiculosum

A cDNA encoding Penicillium funiculosum P(3HB) depolymerase (PhaZPfu) was cloned from a cDNA library. This cDNA contained a 1,020-bp open reading frame (ORF) that encoded 339 amino acids. Edman degradation of PhaZPfu indicated that 20 amino acids from the N terminus function as a signal peptide. Homology analysis revealed that PhaZPfu lacks linker and substrate-binding domains, both of which are observed in bacterial P(3HB) depolymerases. This may account for a weak binding affinity of PhaZPfu to the P(3HB) surface.