Butane metabolism in Pseudomonas butanovora

描述（由申请人提供）：气态和液态烷烃可以作为细菌生长基质。烷烃单加氧酶通过催化烷烃氧化成醇来启动烷烃的代谢。虽然甲烷和液态烷烃（如辛烷）的代谢已经得到了很好的研究，但对短链气态烷烃的氧化却知之甚少。申请人的研究重点是BMOs作为这一未被充分研究的烷烃利用体的代表，以及丁烷代谢的完整途径。先前对三种利用丁烷的细菌的研究结果表明，在收集丁烷的酶以及参与随后的醇代谢的酶之间存在着惊人的多样性。研究人员现在建议将重点放在其中一种细菌上，即butanovora假单胞菌。该项目的具体目标是：1。表征了含BMO的二铁，它与可溶性MMO相似，但不氧化甲烷。2. 申请人发现了两个基因簇，每个基因簇编码一个丁醇脱氢酶和一个假定的丁醛脱氢酶，它们使用平行的电子传递途径。申请人现在建议确定这些平行途径的组成部分。3. 先前的研究表明，该途径中丁烷和中间体对BMO、丁醇脱氢酶和丁醛脱氢酶的产生有独立的调控作用。研究人员将研究丁烷途径在丁烷菌中的诱导调节的分子基础。提出的实验可能为氧化非极性分子的广泛类双铁单加氧酶的底物特异性基础提供独特的见解。平行途径的研究将与其他代谢途径相关，在这些代谢途径中，有毒代谢物必须作为生长支持底物代谢的一部分产生。

DESCRIPTION (provided by applicant): Gaseous and liquid alkanes can serve as bacterial growth substrates. Alkane monooxygenases initiate the metabolism of alkanes by catalyzing the oxidation of the alkanes to alcohols. While metabolism of methane and liquid alkanes (e.g., octane) is well studied, much less is known about the oxidation of short-chain, gaseous alkanes. The applicant's research has focused on BMOs as representatives of this understudied group of alkane utilizers and on the complete pathway of butane metabolism. Previous results with three butane-utilizing bacteria indicated a surprising level of diversity among the enzymes that harvest butane as well as those involved in the subsequent metabolism of the alcohols. The investigators now propose to focus on just one of these bacteria, Pseudomonas butanovora. The specific aims of the project are: 1. Characterize the diiron containing BMO, which is similar to soluble MMO, but does not oxidize methane. 2. The applicants discovered two clusters of genes, each coding for a butanol dehydrogenase and a putative butyraldehyde dehydrogenase, which use parallel pathways of electron transport. The applicant now proposes to identify the components of these parallel pathways. 3. Previous studies indicated independent regulation of the production of BMO, butanol dehydrogenases and butyraldehyde dehydrogenases by butane and intermediates in the pathway. The investigators will examine the molecular basis of the regulation of induction of the butane pathway in P. butanovora. The proposed experiments may provide unique insights to the basis of substrate specificity in the broad class of diiron monooxygenases that oxidize nonpolar molecules. Studies of parallel pathways will be relevant to other metabolic pathways where toxic metabolites are necessarily produced as part of the metabolism of a growth supporting substrate.