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) 34,366. Introduction of cefF 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 cefF gene was introduced in S. lividans in pIJ699 (a vector containing two transcriptional terminators that prevent read-through expression), which suggests that this gene lacks an independent promoter.