Characterization of the cefF gene of Nocardia lactamdurans encoding a 3'-methylcephem hydroxylase different from the 7-cephem hydroxylase

The cefF gene of Nocardia lactamdurans, encoding a functional 2-oxoglutarate-dependent 3'-methylcephem hydroxylase (deacetoxycephalosporin C hydroxylase) has been found to be closely linked to the pcbC gene in the cephamycin C gene cluster. The open-reading frame is 933 bp long and could encode a protein of M(r) 34366. Introduction of ceJF in the cephamycin-non-producer Streptomyces lividans conferred 3'-methylcephem-hydroxylating activity to the transformants but did not result in hydroxylation at carbon 7 of cephamycin. No 3'-methylcephem hydroxylase activity was observed when the ceJF gene was introduced in S. lividans in pIJ699 (a vector containing two transcriptional terminators that prevent readthrough expression), which suggests that this gene lacks an independent promoter.