Genetics of Particulate Methane Monooxygenase

小行星9630645 甲烷氧化细菌，或甲烷氧化菌，含有一种不寻常的膜结合铜单加氧酶，pMMO，它将甲烷氧化为甲醇。 编码这种酶的结构基因（pmo基因）存在于甲烷氧化菌中的双拷贝中，这两种基因都已被证明在甲烷氧化菌荚膜甲基球菌巴斯中具有功能。 本项目的具体目标是确定两组pmo基因是如何表达的，以及在不同条件下这如何影响生理参数，如甲烷氧化能力、生长速率和生长产量。 接下来的方法是使用基因融合来确定野生型中各组基因在不同条件下的表达，并在缺失每组pmo基因的菌株中进行转录分析，以确定基因的转录组织。 然后，在缺失另一组pmo基因的菌株中评估每组pmo基因的表达，以确定基因剂量的这种变化如何影响pMMO活性、生长速率和生长产量。 最后，调控突变体将被分离和表征，以开始分析参与铜调控的分子机制。 这个项目的结果应该提供主要的新的视野到pMMO系统。 一旦获得这些信息，就有可能确定参与产生活性pMMO的其他基因，并确定其表达的细节。 %%% 甲烷氧化细菌，或甲烷氧化菌，含有一种不寻常的膜结合酶，pMMO，将甲烷氧化为甲醇。 由于以下原因，这种酶引起了极大的兴趣。 首先，它具有氧化多种有毒化合物的能力，这些化合物是常见的环境污染物。 这些反应中的许多具有潜在的应用，用于清洁受污染的水和土壤，以及在工业过程中进行环境友好的化学合成。 此外，甲烷氧化菌在土壤中温室气体的循环中很重要，它们在未来的全球变暖中发挥着重要作用。 由于这些原因，重要的是要了解pMMO及其在这些细菌生长中的核心作用。 该项目涉及通过分析其基因以及它们如何产生酶来研究pMMO。 此外，该项目将解决影响pMMO生产的因素，以及我们如何在环境和工业应用中操纵这些因素。 ***

9630645 Lidstrom Methane-oxidizing bacteria, or methanotrophs, contain an unusual membrane-bound copper monooxygenase, the pMMO, that oxidizes methane to methanol. The structural genes encoding this enzyme (pmo genes) are present in dual copies in methanotrophs, both of which have been shown to be functional in the methanotroph Methylococcus capsulatus Bath. The specific objective of this project is to determine how both sets of pmo genes are expressed and how this affects physiological parameters such as methane oxidation capacity, growth rate and growth yield under different conditions. The approach that will be followed is to use gene fusions to define the expression of each set of genes under different conditions in the wild type, and to carry out transcript analysis in strains deleted for each set of pmo genes, to determine the transcriptional organization of the genes. Then, expression of each set of pmo genes will be assessed in the strain deleted for the other set, to determine how this change in gene dosage affects pMMO activity, growth rate and growth yield. Finally, regulatory mutants will be isolated and characterized, to begin to analyze the molecular mechanism involved in copper regulation. The results of this project should provide major new in sights into the pMMO system. Once this information is available, it should be possible to define other genes involved in generating active pMMO, and determine the details of their expression. %%% Methane-oxidizing bacteria, or methanotrophs, contain an unusual membrane-bound enzyme, the pMMO, that oxidizes methane to methanol. This enzyme has attracted a great deal of interest for the following reasons. First, it has the ability to oxidize a variety of toxic compounds that are common environmental pollutants. Many of these reactions have potential applications for cleaning up contaminated water and soil, as well as carrying out environmentally-friendly chemical syntheses in industrial processes. In addition, methanotrophs are important in the cycling of greenhouse gases in the soil, and they play a significant role in the future of global warming. For these reasons, it is important to understand the pMMO and its central role in the growth of these bacteria. This project involves a study of the pMMO by analyzing its genes and how they produce the enzyme. In addition, the project will address the factors that influence production of pMMO and how we can manipulate those factors for both environmental and industrial applications. ***