YbeX of Escherichia coli, a member of the CorC protein family, is encoded in the same operon with ribosome-associated proteins YbeY and YbeZ. Here, we report the involvement of YbeX in ribosomal metabolism. The ΔybeX cells accumulate distinct 16S rRNA degradation intermediates in the 30S particles and the 70S ribosomes. E. coli lacking ybeX has a lengthened lag phase upon outgrowth from the stationary phase. This growth phenotype is heterogeneous at the individual cell level and especially prominent under low extracellular magnesium levels. The ΔybeX strain is sensitive to elevated growth temperatures and to several ribosome-targeting antibiotics that have in common the ability to induce the cold shock response in E. coli. Although generally milder, the phenotypes of the ΔybeX mutant overlap with those caused by ybeY deletion. A genetic screen revealed partial compensation of the ΔybeX growth phenotype by the overexpression of YbeY. These findings indicate an interconnectedness among the ybeZYX operon genes, highlighting their roles in ribosomal assembly and/or degradation.

中文翻译：

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大肠杆菌 YbeX/CorC 参与核糖体代谢

大肠杆菌的 YbeX是 CorC 蛋白家族的成员，与核糖体相关蛋白 YbeY 和 YbeZ 在同一操纵子中编码。在这里，我们报道了 YbeX 参与核糖体代谢的情况。ΔybeX细胞在 30S 颗粒和 70S 核糖体中积累不同的 16S rRNA 降解中间体。缺乏ybeX的大肠杆菌在从固定相生长时具有延长的滞后期。这种生长表型在个体细胞水平上是异质的，并且在低细胞外镁水平下尤其突出。ΔybeX菌株对升高的生长温度和几种核糖体靶向抗生素敏感，这些抗生素具有在大肠杆菌中诱导冷休克反应的共同能力。虽然通常较温和，但ΔybeX突变体的表型与ybeY缺失引起的表型重叠。遗传筛选揭示了YbeY 的过度表达对ΔybeX生长表型的部分补偿。这些发现表明ybeZYX操纵子基因之间存在相互关联，突出了它们在核糖体组装和/或降解中的作用。