Molecular analysis of the pac gene encoding a puromycin N-acetyl transferase from Streptomyces alboniger

Nucleotide sequence of a 906-bp fragment of Streptomyces alboniger DNA containing the gene (pac), which encodes a puromycin N-acetyltransferase (PAC), has been determined. The pac gene contains a 600-nt open reading frame, starting with an ATG codon, which encodes a polypeptide of Mr 21,531; this is consistent with the 23 +/- 1.5 kDa size of the PAC enzyme. High-resolution S1 mapping indicates that transcription starts at or next to a C residue 35 bp upstream from the putative ATG start codon. A 263-bp DNA fragment from the 5' region of the pac gene has promoter activity in the promoter-probe plasmid pIJ486. Its -35 and -10 regions show significant structural homology to the corresponding regions of the hyg gene promoter, but they are different from the promoter sequences of other Streptomyces and Escherichia coli genes.