Proteomic insights into metabolic adaptations in Alcanivorax borkumensis induced by alkane utilization
Proteomic insights into metabolic adaptations in Alcanivorax borkumensis induced by alkane utilization
复制标题
DOI：
10.1128/jb.00072-06
复制
发表时间：
2006-06-01
影响因子：
3.2
通讯作者：
Golyshin, Peter N.
中科院分区：
文献类型：
--
作者：
Sabirova, Julia S.;Ferrer, Manuel;Golyshin, Peter N.
Alcanivorax borkumensis是一种普遍存在的海洋石油降解细菌，具有特殊的生理功能，专门用于烷烃代谢。这种“烃共生”细菌能降解范围非常广的烷烃，但很少降解其他底物。蛋白质组学分析揭示了油气碎屑生活方式的代谢特征。具体来说，十六烷和丙酮酸培养的细胞在97种细胞质和膜相关蛋白的表达上存在差异，这些蛋白的基因似乎是46种假设的操纵子结构的组成部分。在烷烃生长的细胞中，上调的膜蛋白包括三种能够通过末端氧化将烷烃转化为脂肪酸的酶系统，即由众所周知的alkB1基因簇和两种新的烷烃羟基化系统编码的酶，P450细胞色素单加氧酶和假定的黄素结合单加氧酶，以及介导脂肪酸β -氧化的酶。在十六烷生长的细胞中，细胞质蛋白的上调反映了基于脂肪酸饮食的中心代谢，即乙醛酸旁路酶和糖异生途径的酶，能够从脂肪酸中提供关键的代谢中间体，如磷酸烯醇丙酮酸。它们还包括合成核黄素、不饱和脂肪酸和心磷脂的酶，这可能反映了膜适应大量烷烃氧化酶流入引起的扰动所需的膜重组。上调的辅助功能包括脂蛋白释放系统（Lol），可能与生物表面活性剂释放有关，以及在碳过量条件下与碳储存有关的聚羟基烷酸合成酶。三种不同的烷烃氧化体系的存在与A. borkumensis降解石油烃的广泛范围及其在石油污染海洋栖息地的生态成功是一致的。
Alcanivorax borkumensis is a ubiquitous marine petroleum oil-degrading bacterium with an unusual physiology specialized for alkane metabolism. This "hydrocarbonociastic" bacterium degrades an exceptionally broad range of alkane hydrocarbons but few other substrates. The proteomic analysis presented here reveals metabolic features of the hydrocarbonoclastic lifestyle. Specifically, hexadecane-grown and pyruvate-grown cells differed in the expression of 97 cytoplasmic and membrane-associated proteins whose genes appeared to be components of 46 putative operon structures. Membrane proteins up-regulated in alkane-grown cells included three enzyme systems able to convert alkanes via terminal oxidation to fatty acids, namely, enzymes encoded by the well-known alkB1 gene cluster and two new alkane hydroxylating systems, a P450 cytochrome monooxygenase and a putative flavin-binding monooxygenase, and enzymes mediating beta-oxidation of fatty acids. Cytoplasmic proteins up-regulated in hexadecane-grown cells reflect a central metabolism based on a fatty acid diet, namely, enzymes of the glyoxylate bypass and of the gluconeogenesis pathway, able to provide key metabolic intermediates, like phosphoenolpyruvate, from fatty acids. They also include enzymes for synthesis of riboflavin and of unsaturated fatty acids and cardiolipin, which presumably reflect membrane restructuring required for membranes to adapt to perturbations induced by the massive influx of alkane oxidation enzymes. Ancillary functions up-regulated included the lipoprotein releasing system (Lol), presumably associated with biosurfactant release, and polyhydroxyalkanoate synthesis enzymes associated with carbon storage under conditions of carbon surfeit. The existence of three different alkane-oxidizing systems is consistent with the broad range of oil hydrocarbons degraded by A. borkumensis and its ecological success in oil -contaminated marine habitats.