Cloning and heterologous expression of the genes encoding nonspecific electron transport components for a cytochrome P450 system of Saccharopolyspora erythraea involved in erythromycin production.

The forA gene encoding a protein that can function as a NADH:ferredoxin oxidoreductase (For) has been cloned from Saccharopolyspora erythraea, the erythromycin A (ErA) producer. In a previous study For protein, together with the FdxA ferredoxin from the same organism, was shown to be able to reconstitute the cytochrome P450 system responsible for the hydroxylation of 6-deoxyerythronolide B, an intermediate of ErA biosynthesis. Nucleotide sequence data suggest that the cloned forA gene codes for For, the putative pyruvate dehydrogenase component, dihydrolipoamide dehydrogenase, or its close homolog. Overexpression of forA appeared to be toxic to Escherichia coli.