Cloning and Characterization of a Novel Glutathione Transferase Gene from Penicillium chrysogenum

Glutathione transferases (GSTs) are a family of multifunctional proteins that mainly catalyze the conjugation of intracellular glutathione (GSH) to a wide variety of endogenous and exogenous electrophilic compounds. GSTs play important roles in stress tolerance and in the detoxification metabolism in organisms. A novel GST gene, PcgstB, was cloned from penicillin producing fungus Penicillium chrysogenum using RT-PCR. The open reading frame (ORF) of PcgstB was 651bp and encoded a peptide of 216 residues. The deduced amino acids sequence had conserved GST domain and showed 65% identity to the characterized Aspergillus fumigutus gstB. The entire ORF of PcgstB was inserted into vector pTrc99A and transformed into Escherichia coli DH5a. Recombinant PcGstB was overexpressed and its GST activity toward substrate 1-chloro-2,4-dinitrobenzene (CDNB) was validated.