tailieunhanh - Báo cáo khoa học: Heteromer formation of a long-chain prenyl diphosphate synthase from fission yeast Dps1 and budding yeast

Ubiquinone is an essential factor for the electron transfer system and is also a known lipid antioxidant. The length of the ubiquinone isoprenoid side-chain differs amongst living organisms, with six isoprene units in the budding yeastSaccharomyces cerevisiae, eight units in Escherichia coliand 10 units in the fission yeast Schizosaccharomyces pombeand in humans. | ỊFEBS Journal Heteromer formation of a long-chain prenyl diphosphate synthase from fission yeast Dps1 and budding yeast Coq1 Mei Zhang Jun Luo Yuki Ogiyama Ryoichi Saiki and Makoto Kawamukai Department of Applied Bioscience and Biotechnology Faculty of Life and EnvironmentalScience Shimane University Japan Keywords coenzyme Q COQ1 isoprenoid polyprenyl diphosphate synthase ubiquinone Correspondence M. Kawamukai Faculty of Life and EnvironmentalScience Shimane University 1060 Nishikawatsu Matsue 690-8504 Japan Fax 81 852 32 6092 Tel 81 852 32 6587 E-mail kawamuka@ Received 12 April2008 revised 12 May 2008 accepted 15 May 2008 doi Ubiquinone is an essential factor for the electron transfer system and is also a known lipid antioxidant. The length of the ubiquinone isoprenoid side-chain differs amongst living organisms with six isoprene units in the budding yeast Saccharomyces cerevisiae eight units in Escherichia coli and 10 units in the fission yeast Schizosaccharomyces pombe and in humans. The length of the ubiquinone isoprenoid is determined by the product generated by polyprenyl diphosphate synthases poly-PDSs which are classified into homodimer . octa-PDS IspB in E. coli and heterotetramer . deca-PDSs Dps1 and D-less polyprenyl diphosphate synthase Dlp1 in Sc. pombe and in humans types. In this study we characterized the hexa-PDS Coq1 of S. cerevisiae to identify whether this enzyme was a homodimer as in bacteria or a heteromer as in fission yeast . When COQ1 was expressed in an E. coli ispB disruptant only hexa-PDS activity and ubiqui-none-6 were detected indicating that the expression of Coq1 alone results in bacterial enzyme-like functionality. However when expressed in fission yeast Ddps1 and Ddlp1 strains COQ1 restored growth on minimal medium in the Ddlp1 but not Ddps1 strain. Intriguingly ubiquinone-9 and ubiqui-none-10 but not ubiquinone-6 were identified and deca-PDS activity was detected in the