REDUCTION OF OXYGEN BY SULFATE REDUCING BACTERIA

描述：除了他们在生产中的既定作用 大量有毒的硫化氢，硫酸盐还原细菌 已经被证明是有用的，因为它们含有结构类似于 在哺乳动物中发现的更复杂的酶的结构域以及它们在哪里 承担着重要的生物功能。最近， 探索允许将氧气还原为水的系统 这些所谓的“严格厌氧菌”最终发现了一种 含有铁-尿卟啉I作为修复基团的蛋白质。这 化合物，它在一些与基因相关的物质中大量积累 到目前为止，它被认为是一种非代谢物。这一发现，在 除了提供一种将氧气还原为水的新的生理方式 并首次展示了Rubredosin(RD)在厌氧菌中的作用， 增加了尿卟啉I可能在 其他生物。拟议研究的具体目标是：1) 确定酶的三个关键成分中的两个的结构 允许以NADH为电子将氧气还原为水的络合物 供体(第三个的三维结构，即RD，已经 已知的分辨率低于1 A)；2)详细研究电子 NAD-RD-氧化还原酶(NRO)的转移性质；3)描绘 RD和NRO的相互作用区域；4)研究RD和NRO之间的相互作用 RD-氧-氧化还原酶(Roo)的三个氧化还原成分；5)至 确定Roo的血红素C结合组分的化学结构。

DESCRIPTION: Beside their well established role in the production of massive concentrations of toxic hydrogen sulfides, sulfate-reducing bacteria have proven useful since they contain proteins whose structure is similar to domains of more complex enzymes which are found in mammals and where they are responsible for important biological functions. Recently, the exploration of the system that allows the reduction of oxygen to water in these so-called "strict anaerobes" has culminated with the discovery of a protein that contains Fe-Uroporphyrin I as a prosthetic group. This compound, which accumulates in large amounts in some genetically-linked porphyrias, was so far considered as a non-metabolite. This discovery, in addition to providing a new physiological way of reducing oxygen to water and of showing for the first time a role for rubredoxin (Rd) in an anaerobe, has raised the possibility that Uroporphyrin I may play important roles in other organisms. The specific aims of the proposed research are: 1) to determine the structure of two of the three key components of the enzymatic complex that allows the reduction of oxygen to water with NADH as electron donor (the three-dimensional structure of the third, namely Rd, is already known to a resolution below 1 A); 2) to examine in detail the electron transferring properties of the NAD-Rd-oxidoreductase (NRO); 3) to delineate the interacting domain between Rd and NRO; 4) to study the interplay between the three redox components of the Rd-Oxygen-oxidoreductase (ROO); 5) to determine the chemical structure of the heme c-binding component of ROO.