Department of Microbiology, University of Georgia, Athens, GA, USA.
Sci Rep. 2017 Oct 11;7(1):12971. doi: 10.1038/s41598-017-13030-x.
Members of the broadly distributed Rid/YER057c/UK114 protein family have imine/enamine deaminase activity, notably on 2-aminoacrylate (2AA). Strains of Salmonella enterica, and other organisms lacking RidA, have diverse growth phenotypes, attributed to the accumulation of 2AA. In S. enterica, 2AA inactivates a number of pyridoxal 5'-phosephate(PLP)-dependent enzymes, some of which have been linked to the growth phenotypes of a ridA mutant. This study used transcriptional differences between S. enterica wild-type and ridA strains to explore the breadth of the cellular consequences that resulted from accumulation of 2AA. Accumulation of endogenously generated 2AA in a ridA mutant resulted in lower expression of genes encoding many flagellar assembly components, which led to a motility defect. qRT-PCR results were consistent with the motility phenotype of a ridA mutant resulting from a defect in FlhDC activity. In total, the results of comparative transcriptomics correctly predicted a 2AA-dependent motility defect and identified additional areas of metabolism impacted by the metabolic stress of 2AA in Salmonella enterica. Further, the data emphasized the value of integrating global approaches with biochemical genetic approaches to understand the complex system of microbial metabolism.
广泛分布的 Rid/YER057c/UK114 蛋白家族的成员具有亚胺/烯胺脱氨酶活性，特别是对 2-氨基丙烯酸（2AA）。缺乏 RidA 的沙门氏菌和其他生物体具有不同的生长表型，归因于 2AA 的积累。在沙门氏菌中，2AA 使许多依赖吡哆醛 5'-磷酸（PLP）的酶失活，其中一些酶与 ridA 突变体的生长表型有关。本研究使用沙门氏菌野生型和 ridA 菌株之间的转录差异来探索由于 2AA 的积累而导致的细胞后果的广度。在 ridA 突变体中积累内源性产生的 2AA 导致编码许多鞭毛组装成分的基因表达降低，从而导致运动缺陷。qRT-PCR 结果与 ridA 突变体的运动表型一致，这是由于 FlhDC 活性缺陷所致。总的来说，比较转录组学的结果正确预测了 2AA 依赖性的运动缺陷，并确定了沙门氏菌中 2AA 代谢应激影响的其他代谢区域。此外，数据强调了将全局方法与生化遗传方法相结合以理解微生物代谢复杂系统的价值。
