A subunit of decaprenyl diphosphate synthase stabilizes octaprenyl diphosphate synthase in Escherichia coli by forming a high-molecular weight complex

The length of the isoprenoid-side chain in ubiquinone, an essential component of the electron transport chain, is defined by poly-prenyl diphosphate synthase, which comprises either homomers (e.g., IspB in Escherichia coli) or heteromers (e.g., decaprenyl diphosphate synthase (Dps1) and D-less polyprenyl diphosphate synthase (Dlp1) in Schizosaccharomyces pombe and in humans). We found that expression of either dlp1 or dps1 recovered the thermo-sensitive growth of an E. coli ispBR321A mutant and restored IspB activity and production of Coenzyme Q-8. IspB interacted with Dlp1 (or Dps1), forming a high-molecular weight complex that stabilized IspB, leading to full functionality.Structured summary:MINT-7385426:Dlp1 (uniprotkb:Q86YH6) and IspB (uniprotkb:P0AD57) physically interact (MI:0915) by blue native page (MI:0276)MINT-7385083, MINT-7385058:IspB (uniprotkb:P0AD57) and IspB (uniprotkb:P0AD57) bind (MI:0407) by blue native page (MI:0276)MINT-7385413:Dlp1 (uniprotkb:O13851) and IspB (uniprotkb:P0AD57) physically interact (MI:0915) by blue native page (MI:0276)MINT-7385024:IspB (uniprotkb:P0AD57) physically interacts (MI:0915) with Dps1 (uniprotkb:O43091) by pull down (MI:0096)MINT-7385041:IspB (uniprotkb:P0AD57) physically interacts (MI:0915) with Dlp1 (uniprotkb:O13851) by pull down (MI:0096)MINT-7385388:IspB (uniprotkb:P0AD57) and Dps1 (uniprotkb:O43091) physically interact (MI:0915) by blue native page (MI:0276)