Structural and Functional Analysis of Bacterial Formate Channels

细菌甲酸通道的结构和功能分析

• 批准号: 197321781
• 负责人: Professor Dr. Oliver Einsle
• 金额: --
• 依托单位: Institut für Biochemie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/197321781?language=en
• 关键词: Structural; Functional; Analysis; Bacterial; Formate

Formate constitutes a major metabolite in bacteria and plays a key role as electron donor in various respiratory pathways. The transport of formate across biological membranes is mediated by the formate channel FocA, a member of the FNT family of membrane transporters. Our three-dimensional structure of the protein from Salmonella typhimurium at low pH showed a concerted and cooperative set of conformational changes of the N-terminus that form the basis for a functional switch from the export of the formate anion by facilitated diffusion at high external pH to secondary active formate/H+ import at a pH below 6.8. This corresponds to a metabolic shift from cytoplasmic formate production by pyruvate:formate lyase (PFL) and periplasmic, respiratory formate oxidation to cytoplasmic formate disproportionation at the formate:hydrogen lyase complex (FHL). We propose to continue and extend our work on FocA to include an electrophysiological characterization of the formate channel and its dependency on the proton motive force in lipid bilayers. We will further analyse the mechanism of pH sensing in FocA by site-directed mutagenesis and investigate the subcellular localization of the protein and its interaction with physiological partners such as PFL or the FHL complex.

甲酸是细菌的主要代谢物，在各种呼吸途径中作为电子供体发挥着关键作用。甲酸跨生物膜的转运是由甲酸通道 FocA 介导的，FocA 是膜转运蛋白 FNT 家族的成员。我们对低 pH 条件下鼠伤寒沙门氏菌蛋白质的三维结构显示出一组协调一致的 N 末端构象变化，这些变化构成了在高外部 pH 条件下通过促进扩散从甲酸根阴离子输出进行功能转换的基础在 pH 值低于 6.8 时导入二次活性甲酸盐/H+。这对应于从丙酮酸：甲酸裂解酶（PFL）和周质呼吸甲酸氧化产生的细胞质甲酸到甲酸：氢裂解酶复合物（FHL）处的细胞质甲酸歧化的代谢转变。我们建议继续并扩展我们对 FocA 的工作，包括甲酸通道的电生理学特征及其对脂质双层中质子动力的依赖性。我们将通过定点突变进一步分析 FocA 中 pH 传感的机制，并研究该蛋白的亚细胞定位及其与 PFL 或 FHL 复合物等生理伙伴的相互作用。

项目成果

The formate/nitrite transporter family of anion channels

阴离子通道的甲酸盐/亚硝酸盐转运蛋白家族

• DOI: 10.1515/hsz-2012-0339
• 发表时间: 2013-06-01
• 期刊: Journal of chemical information and modeling
• 作者: Wei Lü;Juan Du;Nikola J. Schwarzer;T. Wacker;S. Andrade;O. Einsle
• 通讯作者: O. Einsle