Carbohydrate Catabolism in Phaeobacter inhibens DSM 17395, a Member of the Marine Roseobacter Clade
Carbohydrate Catabolism in Phaeobacter inhibens DSM 17395, a Member of the Marine Roseobacter Clade
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DOI：
10.1128/aem.00719-14
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发表时间：
2014-08-01
影响因子：
4.4
通讯作者：
Rabus, Ralf
中科院分区：
文献类型：
--
作者：
Wiegmann, Katharina;Hensler, Michael;Rabus, Ralf
由于基因组分析不允许明确的重建的运输，catalysts，和底物特异性调节几个重要的碳水化合物在Phaeacetylglucosebens DSM 17395，蛋白质组学和代谢组学分析的N-乙酰葡糖胺，甘露醇，蔗糖，葡萄糖和木糖生长的细胞进行，以关闭这一知识差距。这些碳水化合物可以通过外膜部分中鉴定的孔蛋白穿过外膜。对于跨细胞质膜的运输，鉴定了碳水化合物特异性ABC运输系统。它们的编码基因大多与各自的“分解代谢”和“调节”基因共定位。N-乙酰葡糖胺的降解通过N-乙酰葡糖胺-6-磷酸和葡糖胺-6-磷酸直接进行果糖-6-磷酸;三种酶中的两种是新预测和鉴定的。甘露醇通过果糖分解代谢，蔗糖通过果糖和葡萄糖分解代谢，葡萄糖通过葡萄糖-6-磷酸分解代谢，木糖通过木酮糖-5-磷酸分解代谢。在预测参与摄取、调节和降解的30种蛋白质中，28种通过蛋白质组学鉴定，19种首次被分配到各自的功能。外周降解途径进入Entner-Doudoroff（艾德）途径，该途径与Embden-Meyerhof-Parnas（EMP）途径的下分支相连。这些途径的酶组分在与所测试的五种碳水化合物中的任何一种一起生长的P.lubens DSM 17395细胞中显示出比在琥珀酸盐生长的细胞中更高的丰度。相反地，在琥珀酸利用期间启动异源发生。虽然三羧酸（TCA）循环蛋白基本保持不变，但其代谢产物的丰度曲线反映了不同底物的不同生长速率。参与重建的分解代谢途径和中心代谢的74个基因的同源物存在于各种蔷薇属进化枝成员中。
Since genome analysis did not allow unambiguous reconstruction of transport, catabolism, and substrate-specific regulation for several important carbohydrates in Phaeobacter inhibens DSM 17395, proteomic and metabolomic analyses of N-acetylglucosamine-, mannitol-, sucrose-, glucose-, and xylose-grown cells were carried out to close this knowledge gap. These carbohydrates can pass through the outer membrane via porins identified in the outer membrane fraction. For transport across the cytoplasmic membrane, carbohydrate-specific ABC transport systems were identified. Their coding genes mostly colocalize with the respective "catabolic" and "regulatory" genes. The degradation of N-acetylglucosamine proceeds via N-acetylglucosamine-6-phosphate and glucosamine-6-phosphate directly to fructose-6-phosphate; two of the three enzymes involved were newly predicted and identified. Mannitol is catabolized via fructose, sucrose via fructose and glucose, glucose via glucose-6-phosphate, and xylose via xylulose-5-phosphate. Of the 30 proteins predicted to be involved in uptake, regulation, and degradation, 28 were identified by proteomics and 19 were assigned to their respective functions for the first time. The peripheral degradation pathways feed into the Entner-Doudoroff (ED) pathway, which is connected to the lower branch of the Embden-Meyerhof-Parnas (EMP) pathway. The enzyme constituents of these pathways displayed higher abundances in P. inhibens DSM 17395 cells grown with any of the five carbohydrates tested than in succinate-grown cells. Conversely, gluconeogenesis is turned on during succinate utilization. While tricarboxylic acid (TCA) cycle proteins remained mainly unchanged, the abundance profiles of their metabolites reflected the differing growth rates achieved with the different substrates tested. Homologs of the 74 genes involved in the reconstructed catabolic pathways and central metabolism are present in various Roseobacter clade members.