中文摘要：

离氨酸 acetylation 是最丰富的 translational 以后修正之一。然而，在细菌的这修正的生理的角色大部分是未知的。以前的蛋白质 acetylome 分析证明 Escherichia coli adenosylmethionine synthase (地席) 在 vivo，而是这修正的生物功能经历 acetylation 仍然需要被揭开。在这研究， E 的地席。coli 过去表示、净化。随后的集体 spectrometry 分析证明蛋白质的 12 离氨酸残余是 acetylated。指导地点的 mutagenesis 分析被执行，结果证明 acetylated 离氨酸残余在地席的酶的活动起重要作用。下次， deacetylation 试金被把 CobB 用作 deacetylase 执行，并且结果显示出那 CobB 能在 vitro 的 deacetylate 地席。另外， acetylated 的酶的活动和 deacetylated 地席在 vitro 被比较，并且结果证明 acetylation 在它的酶的活动导致了减少，它能被 CobB deacetylation 颠倒。总的来说，我们的数据建议 CobB 调制 E 的酶的活动。在 vitro 的 coli 地席。

英文摘要：

Lysine acetylation is one of the most abundant post-translational modifications. However, physiological roles of this modification in bacteria are largely unknown. Previous protein acety- Iome analysis showed that Escherichia coli adenosylmethionine synthase （MAT） undergoes acetylation in vivo, but the biological functions of this modification still need to be uncovered. In this study, MAT of E. coil was over-expressed and purified. Subsequent mass spectrometry ana- lysis showed that 12 lysine residues of the protein were acetylated. Site-directed mutagenesis analysis was performed and the results showed that acetylated lysine residues play important roles in the enzymatic activity of MAT. Next, deacetylation assay was performed by using CobB as the deacetylase, and the results showed that CobB could deacetylate MAT in vitro. In add- ition, the enzymatic activities of acetylated and deacetylated MAT were compared in vitro, and results showed that acetylation led to a decrease in its enzymatic activity, which could be reversed by CobB deacetylation. Altogether, our data suggest that CobB modulates the enzym- atic activity of E, coil MAT in vitro.