Institute of Biochemistry, University of Cologne, 50674 Cologne, Germany.
Appl Microbiol Biotechnol. 2011 Jan;89(2):327-35. doi: 10.1007/s00253-010-2855-1. Epub 2010 Aug 31.
Succinic acid is excreted during anaerobiosis by many bacteria, and manifold applications are known making the biotechnological production of succinate attractive. Although the pathways for succinate formation are known, succinate export is not understood in most of the succinate producing bacteria. Here, we present a bioinformatic approach for identification of a putative succinate export system in Corynebacterium glutamicum. The subsequent screening revealed that a mutant in the gene cg2425 is impaired in succinate production or transport under anaerobic conditions. A function of the Cg2425 protein as import system was excluded. In contrast, a role of the Cg2425 protein as succinate export system was indicated by accumulation of increased amounts of internal succinate under anaerobic conditions in a Cg2425-dependent manner and a concomitant impairment of external succinate accumulation. In conclusion, we propose that Cg2425 participates in succinate export in C. glutamicum and suggest the name SucE for the protein.
琥珀酸是许多细菌在无氧条件下排泄的物质，其具有多种应用，因此生物制造琥珀酸具有吸引力。虽然已经知道了琥珀酸形成的途径，但在大多数产琥珀酸的细菌中，琥珀酸的外排并不清楚。在这里，我们提出了一种生物信息学方法来鉴定谷氨酸棒杆菌中可能的琥珀酸输出系统。随后的筛选表明，基因 cg2425 中的突变体在厌氧条件下的琥珀酸生产或运输中受到损害。排除了 Cg2425 蛋白作为输入系统的功能。相反，Cg2425 蛋白作为琥珀酸输出系统的作用是通过在厌氧条件下以 Cg2425 依赖的方式积累增加的内部琥珀酸的量和同时损害外部琥珀酸的积累来指示的。总之，我们提出 Cg2425 参与了谷氨酸棒杆菌中的琥珀酸输出，并建议将该蛋白命名为 SucE。
