The manganese superoxide dismutase from the penicillin producer Penicillium chrysogenum

The antioxidant enzyme superoxide dismutase has been studied in order to define mechanisms for the influence of oxygen on penicillin production. Manganese-containing SOD activity was purified from penicillin-producing cultures of the filamentous fungus Penicillium chrysogenum and reverse genetics was used to identify full-length cDNA and genomic clones. Sequence analysis revealed a 630-bp ORF containing three exons and two introns with fungal consensus splice-site junctions. The deduced amino-acid sequence (210 amino acids; 23.13 kDa) includes conserved residues required for enzymatic activity and metal binding, and shares significant similarity with Mn- and Fe-containing superoxide dismutases. The sod gene is present as a single copy in the genome of different P. chrysogenum strains and its expression level is not correlated with penicillin-G productivity.