...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The FEBS journal >Structural basis for cyclodextrin recognition by Thermoactinomyces vulgaris cyclo/maltodextrin-binding protein
【24h】

Structural basis for cyclodextrin recognition by Thermoactinomyces vulgaris cyclo/maltodextrin-binding protein

机译：寻常嗜热放线菌环/麦芽糊精结合蛋白识别环糊精的结构基础

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

The crystal structure of a Thermoactinomyces vulgaris cyclo/maltodextrin-binding protein (TvuCMBP) complexed with gamma-cyclodextrin has been determined. Like Escherichia coli maltodextrin-binding protein (EcoMBP) and other bacterial sugar-binding proteins, TvuCMBP consists of two domains, an N- and a C-domain, both of which are composed of a central beta-sheet surrounded by alpha-helices; the domains are joined by a hinge region containing three segments. gamma-Cyclodextrin is located at a cleft formed by the two domains. A common functional conformational change has been reported in this protein family, which involves switching from an open form to a sugar-transporter bindable form, designated a closed form. The TvuCMBP-gamma-cyclodextrin complex structurally resembles the closed form of EcoMBP, indicating that TvuCMBP complexed with gamma-cyclodextrin adopts the closed form. The fluorescence measurements also showed that the affinities of TvuCMBP for cyclodextrins were almost equal to those for maltooligosaccharides. Despite having similar folds, the sugar-binding site of the N-domain part of TvuCMBP and other bacterial sugar-binding proteins are strikingly different. In TvuCMBP, the side-chain of Leu59 protrudes from the N-domain part into the sugar-binding cleft and orients toward the central cavity of gamma-cyclodextrin, thus Leu59 appears to play the key role in binding. The cleft of the sugar-binding site of TvuCMBP is also wider than that of EcoMBP. These findings suggest that the sugar-binding site of the N-domain part and the wide cleft are critical in determining the specificity of TvuCMBP for gamma-cyclodextrin.
机译：已确定与γ-环糊精复合的寻常嗜热放线菌环/麦芽糊精结合蛋白（TvuCMBP）的晶体结构。像大肠杆菌的麦芽糖糊精结合蛋白（EcoMBP）和其他细菌糖结合蛋白一样，TvuCMBP由两个域组成，即N域和C域，这两个域均由被β-螺旋包围的中央β-折叠构成。域由包含三个片段的铰链区连接。 γ-环糊精位于由两个结构域形成的裂缝中。已经报道了该蛋白质家族中常见的功能构象变化，其涉及从开放形式转换为糖转运体可结合形式，称为封闭形式。 TvuCMBP-γ-环糊精复合物在结构上类似于EcoMBP的封闭形式，表明与γ-环糊精复合的TvuCMBP采用封闭形式。荧光测量还表明，TvuCMBP对环糊精的亲和力几乎与麦芽低聚糖的亲和力相等。尽管具有相似的折叠，TvuCMBP的N结构域部分的糖结合位点和其他细菌糖结合蛋白却截然不同。在TvuCMBP中，Leu59的侧链从N结构域突出到糖结合裂隙中，并朝向γ-环糊精的中央腔定向，因此Leu59似乎在结合中起关键作用。 TvuCMBP的糖结合位点的裂口也比EcoMBP的裂口宽。这些发现表明，N结构域部分的糖结合位点和宽裂在确定TvuCMBP对γ-环糊精的特异性中至关重要。

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