Nucleotide Sequence of the Gene Cluster Containing the mphB Gene for Macrolide 2'-Phosphotransferase II.

Escherichia coli BM2506 produced macrolide 2'-phosphotransferase II [MPH (2') II]. A gene for MPH (2') II, designated mphB, is located on plasmids pTZ3721 and pTZ3723 in E. coli BM2506. In the present study, we determined the nucleotide sequence of the 6.5-kb EcoRI-PstI fragment containing mphB on pTZ3721. The DNA region of 6.5-kb EcoRI-PstI fragment contained five open reading frames (ORFs). ORF4 corresponded to mphB. Respective products deduced from ORF1, ORF2, ORF3, and ORF5 were similar to the penicillin-binding protein 4 of Streptomyces lactamduras, the repressor protein AcrR of the acrAB operon, the enzyme RdmC involved in the biosynthesis of the antibiotic aklavinone, and IS801 transposase-like protein from Pseudomonas pseudoalcakigenes, respectively. Among these genes, ORF2, ORF3, and mphB formed a gene cluster with ORF2 in the lead sequence. Our results suggest that mphB may originate from an operon related to antibiotic biosynthesis.