Unusual enzyme complexes in anaerobic aromatic metabolism of Geobacter metallireducens

金属还原地杆菌厌氧芳香代谢中的异常酶复合物

• 批准号: 71841327
• 负责人: Professor Dr. Matthias Boll
• 金额: --
• 依托单位: Forschungsschwerpunkt Mikrobiologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/71841327?language=en
• 关键词: Unusual; enzyme; complexes; anaerobic; aromatic

The anaerobic aromatic metabolism has extensively been studied in facultatively anaerobic bacteria. Due to limitations in the overall energy metabolism many key enzymatic processes differ in obligately anaerobic bacteria. E.g., the ATP-dependent, dearomatizing class I benzoyl-CoA reductase (BcrABCD-subunits, FeS-cofactors) is replaced by an ATP-independent class II BCR in obligate anaerobes (BamBCDEFGHI-subunits, W/FeS/SeCys/FAD-cofactors). In the last funding period we have isolated and characterized the previsouly unknown W/FeS-cluster containing active site subunits BamBC from Geobacter metallireducens, and the crystal structure of BamBC enabled first insights into the mechanism. Another unusual enzyme complex in G. metallireducens is p-cresol methylhydroxylase (PCMH, PcmGIJ-subunits) catalyzing the first steps in anaerobic p-cresol metabolism. It differs from other PCMHs by its tight location in the membrane, possibly in association with a cytochrome bc1-like complex (PcmCDEF-subunits) and by its unusual subunit/cofactor-composition. In the last funding period we have isolated and characterized the soluble PmcGIJ components. In the next funding period both entire enzyme complexes of the class II BCR and PCMH including the so far missing components will be isolated and studied by kinetic, spectroscopic and structural methodologies. A main objective is to obtain insights into the function of novel multi component enzyme complexes involved in unusual energy transduction/conservation processes in obligately anaerobic bacteria.

厌氧芳香代谢在兼性厌氧细菌中已被广泛研究。由于整体能量代谢的限制，许多关键的酶促过程在专性厌氧细菌中不同。例如，在一个示例中，在专性厌氧菌中，ATP依赖性的、脱芳构化的I类苯甲酰辅酶A还原酶（BcrABCD-亚基，FeS-辅因子）被ATP非依赖性的II类BCR（BamBCDEFGHI-亚基，W/FeS/SeCys/FAD-辅因子）取代。在上一个资助期间，我们已经分离和表征了以前未知的W/FeS-簇，其中含有来自Geetron metallirereducens的活性位点亚基BamBC，BamBC的晶体结构使我们能够首次深入了解该机制。G.金属还原酶是对甲酚甲基羟化酶（PCMH，PcmGIJ-亚基），催化厌氧对甲酚代谢的第一步。它不同于其他PCMHs的紧密位置在膜上，可能与细胞色素bc 1样复合物（PcmCDEF亚基）和其不寻常的亚基/辅因子组合物。在上一个资助期，我们已经分离和表征了可溶性PmcGIJ组分。在下一个资助期间，II类BCR和PCMH的整个酶复合物，包括迄今为止缺失的组分，将通过动力学，光谱和结构方法进行分离和研究。一个主要目的是获得洞察的功能，新的多组分酶复合物参与不寻常的能量转换/保存过程中专性厌氧细菌。