Department of Applied Bioscience and Biotechnology, Faculty of Life and Environmental Science, Shimane University, Matsue, Japan.
FEBS Lett. 2010 Feb 19;584(4):652-6. doi: 10.1016/j.febslet.2009.12.029. Epub 2010 Jan 5.
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 ispB(R321A) 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.
泛醌是电子传递链的必需组成部分，其异戊烯侧链的长度由聚异戊烯二磷酸合酶定义，该酶由同二聚体（例如大肠杆菌中的 IspB）或异二聚体（例如裂殖酵母中的 decaprenyl diphosphate synthase（Dps1）和 D-less polyprenyl diphosphate synthase（Dlp1）以及人类）组成。我们发现表达 dlp1 或 dps1 均可恢复 E. coli ispB(R321A)突变体的热敏生长，并恢复 IspB 活性和 Coenzyme Q-8 的产生。IspB 与 Dlp1（或 Dps1）相互作用，形成一个高分子量复合物，稳定 IspB，使其具有完整的功能。
