Xu X, Matsuno-Yagi A, Yagi T
Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California 92037.
Biochemistry. 1992 Aug 4;31(30):6925-32. doi: 10.1021/bi00145a009.
In previous reports from our laboratory, the three structural genes (NQO1, NQO2, and NQO3) of the energy-transducing NADH-quinone oxidoreductase of Paracoccus denitrificans were characterized [Xu, X., Matsuno-Yagi, A., & Yagi, T. (1991) Biochemistry 30, 6422-6428; (1991) Biochemistry 30, 8678-8684; (1992) Arch. Biochem. Biophys. 296, 40-48]. In this report, the four structural genes NQO4, NQO5, NQO6, and NQO7 of the same Paracoccus denitrificans oxidoreductase were cloned and sequenced. On the basis of sequence homology and immunological cross-reactivity, these genes encode counterparts of the 49-, 30-, and 20-kDa polypeptides and the mitochondrial DNA ND3 polypeptides of bovine mitochondrial complex I. These seven structural genes were found to be located in the same gene cluster. The order of the seven structural genes of the Paracoccus NADH-quinone oxidoreductase in the gene cluster is NQO7, NQO6, NQO5, NQO4, NQO2, NQO1, and NQO3. Upstream of the NQO7 gene, an open reading frame encoding a predicted polypeptide homologous to the UV repair enzyme A of Escherichia coli and Micrococcus lysodeikticus was detected. The 5'-terminus of the gene cluster carrying the Paracoccus NADH-quinone oxidoreductase was studied, and the possible promoter region is discussed. The NQO4 and NQO5 genes appear to code for the M(r) 48,000 and 21,000 polypeptides of the isolated Paracoccus NADH dehydrogenase complex [Yagi, T. (1986) Arch. Biochem. Biophys. 250, 302-311] on the basis of amino acid analyses and N-terminal protein sequence analyses. The antisera to the bovine complex I 49- and 30-kDa polypeptides cross-reacted with the Paracoccus 48- and 21-kDa subunits, respectively.
在我们实验室之前的报告中，已对反硝化副球菌能量转换型NADH-醌氧化还原酶的三个结构基因（NQO1、NQO2和NQO3）进行了表征[Xu, X., Matsuno-Yagi, A., & Yagi, T. (1991) Biochemistry 30, 6422 - 6428; (1991) Biochemistry 30, 8678 - 8684; (1992) Arch. Biochem. Biophys. 296, 40 - 48]。在本报告中，克隆并测序了同一反硝化副球菌氧化还原酶的四个结构基因NQO4、NQO5、NQO6和NQO7。基于序列同源性和免疫交叉反应性，这些基因编码牛线粒体复合物I的49 kDa、30 kDa和20 kDa多肽以及线粒体DNA ND3多肽的对应物。发现这七个结构基因位于同一基因簇中。反硝化副球菌NADH-醌氧化还原酶的七个结构基因在基因簇中的顺序是NQO7、NQO6、NQO5、NQO4、NQO2、NQO1和NQO3。在NQO7基因的上游，检测到一个开放阅读框，其编码的预测多肽与大肠杆菌和溶壁微球菌的紫外线修复酶A同源。研究了携带反硝化副球菌NADH-醌氧化还原酶的基因簇的5'末端，并讨论了可能的启动子区域。基于氨基酸分析和N端蛋白质序列分析，NQO4和NQO5基因似乎编码分离的反硝化副球菌NADH脱氢酶复合物的48000 Mr和21000 Mr多肽[Yagi, T. (1986) Arch. Biochem. Biophys. 250, 302 - 311]。牛复合物I的49 kDa和30 kDa多肽的抗血清分别与反硝化副球菌的48 kDa和21 kDa亚基发生交叉反应。
