Analysis of the tunicamycin biosynthetic gene cluster of reveals new insights into tunicamycin production and immunity.

The tunicamycin biosynthetic gene cluster of consists of 14 genes () with a high degree of apparent translational coupling. Transcriptional analysis revealed that all of these genes are likely to be transcribed as a single operon from two promoters, p1 and p2. In frame deletion analysis revealed that just six of these genes () are essential for tunicamycin production in the heterologous host , while five () with likely counterparts in primary metabolism are not necessary, but presumably ensure efficient production of the antibiotic at the onset of tunicamycin biosynthesis. Three genes are implicated in immunity; , which encode a two component ABC transporter presumably required for export of the antibiotic, and , which encodes a putative SAM-dependent methyltransferase. Expression of or in conferred resistance to exogenous tunicamycin. The results presented here provide new insights into tunicamycin biosynthesis and immunity.