Coenzyme Q biosynthesis in the biopesticide Shenqinmycin-producing Pseudomonas aeruginosa strain M18

Coenzyme Q (ubiquinone) is a redox-active isoprenylated benzoquinone commonly found in living organisms. The biosynthetic pathway for this lipid has been extensively studied in Escherichia coli and Saccharomyces cerevisiae ; however, little is known in Pseudomonas aeruginosa . In this study, we observed that CoQ 9 is the predominant coenzyme Q synthesized by the Shenqinmycin-producing strain M18. BLASTP and domain organization analyses identified 15 putative genes for CoQ biosynthesis in M18. The roles of 5 of these genes were genetically and biochemically investigated. PAM18_4662 encodes a nonaprenyl diphosphate synthase (Nds) and determines the number of isoprenoid units of CoQ 9 in M18. PAM18_0636 ( coq7 PA ) and PAM18_5179 ( ubiJ PA ) are essential for aerobic growth and CoQ 9 biosynthesis. Deletion of ubiJ PA , ubiB PA and ubiK PA led to reduced CoQ biosynthesis and an accumulation of the CoQ 9 biosynthetic intermediate 3-nonaprenylphenol (NPP). Moreover, we also provide evidence that the truncated UbiJ PA interacts with UbiB PA and UbiK PA to affect CoQ 9 biosynthesis by forming a regulatory complex. The genetic diversity of coenzyme Q biosynthesis may provide targets for the future design of specific drugs to prevent P. aeruginosa -related infections.