...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >Identification of the Structural Subunits Required for Formation of the Metal Centers in Subunit I of Cytochrome c Oxidase of Rhodobacter sphaeroides
【24h】

Identification of the Structural Subunits Required for Formation of the Metal Centers in Subunit I of Cytochrome c Oxidase of Rhodobacter sphaeroides

机译：球形红球菌细胞色素c氧化酶亚基I中形成金属中心所需的结构亚基的鉴定

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Genetic manipulation of the aa_3-type cytochrome c oxidase of Rhodobacter sphaeroides was used to determine the minimal structural subunit associations required for the assembly of the heme A and copper centers of subunit I. In the absence of the genes for subunits II and III, expression of the gene for subunit I in Rb. sphaeroides allowed purification of a form of free subunit I(subunit I_a) that contained a single heme A. No copper was present in this protein, indicating that the heme a_3-Cu_B active site was not assembled. In ce4lls expressing the genes for subunits I and II, but not subunit III, two oxidase forms were synthesized that were copurified by histidine affinity chromatography and separated by anion-exchange chromatography. One form was a highly active subunit I-II oxidase containing a full complement of structurally normal metal centers. This shows that association of subunit II with subunit I is required for stable formation of the active site in subunit I. In contrast, subunit III is not required for the formation of any of the metal centers or for the production of an oxidase with wild-type activity. The second product of the cells lacking subunit III was a large amount of a free form of subunit I that appeared identifcal to subunit I_a. Since significant amounts of subunit I_a were also isolated form wild-type cells, it is likely that subunit I_a will be present in any preparation of the aa_a-type oxidase isolated via an affinity tag on subunit I.
机译：球形红球菌aa_3型细胞色素c氧化酶的遗传操作用于确定组装亚基I的血红素A和铜中心所需的最小结构亚基缔合。在缺乏亚基II和III的基因的情况下，表达Rb中亚基I的基因的表达。 sphaeroides允许纯化包含单个血红素A的游离亚基I（亚基I_a）的形式。该蛋白质中不存在铜，表明血红素a_3-Cu_B活性位点未组装。在表达亚基I和II而不是亚基III的基因的ce4ll中，合成了两种氧化酶形式，其通过组氨酸亲和色谱法共同纯化，并通过阴离子交换色谱法分离。一种形式是高活性的亚基I-II氧化酶，包含结构正常金属中心的完整互补。这表明亚基II与亚基I的缔合是稳定形成亚基I中活性位点所必需的。相反，亚基III不需要形成任何金属中心或生产带有野生型金属的氧化酶。键入活动。缺乏亚基III的细胞的第二个产物是大量的游离形式的亚基I，表现出与亚基I_a相同。由于还从野生型细胞中分离出大量亚基I_a，因此亚基I_a可能存在于通过亚基I上的亲和标签分离的任何aa_a型氧化酶制剂中。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号