Copper Acquisition by Methanotrophs.

描述（由申请人提供）：甲烷是人类活动在美国排放的第二大温室气体。由于甲烷在捕获辐射方面的有效性，它被认为比二氧化碳对环境的危害更大。甲烷氧化菌是革兰氏阴性菌，可以代谢甲烷，并可能提供修复气体的途径。在甲烷代谢的第一步，甲烷氧化菌使用一种称为颗粒甲烷单加氧酶（pMMO）的整体膜蛋白将甲烷氧化成甲醇。pMMO是一种依赖铜的酶，因此甲烷氧化菌对铜的需求量增加。在限制Cu的条件下，一些甲烷氧化菌分泌一种天然产物样的小分子，以高亲和力结合Cu。这种分子被称为甲烷菌素（Mbn），被重新内化到细胞中

DESCRIPTION (provided by applicant): Methane is the second most prevalent greenhouse gas emitted in the United States as a result of human activity. Because of methane's effectiveness at trapping radiation, it is considered significantly more deleterious to the environment than carbon dioxide. Methanotrophs are gram-negative bacteria that metabolize methane and may provide routes for the remediation of the gas. In the first step of metabolizing methane, methanotrophs use an integral membrane protein called particulate methane monooxygenase (pMMO) to oxidize methane to methanol. pMMO is copper-dependent enzyme, and thus methanotrophs have an elevated requirement for copper (Cu). Under conditions of limiting Cu, some methanotrophs secrete a small natural product-like molecule that binds Cu with high affinity. This molecule, called methanobactin (Mbn), is re- internalized into the cell in its Cu-loaded form to satisfy the cell's copper needs. The proposed research will characterize the transporter implicated in the re-internalization of the Cu-Mbn complex in two different methanotrophs. This work will provide insight into the mechanism by which a key requirement for methane metabolism, the acquisition of Cu for pMMO's cofactor, is fulfilled. Additionally, it will provide insight on methanotrophic bacterial homeostasis.