Hong Hye-Rim, Prince Cassidy R, Wu Letian, Lin Isabella N, Feaga Heather A
Department of Microbiology, Cornell University, Ithaca, NY 14853.
bioRxiv. 2024 Oct 19:2024.10.18.618948. doi: 10.1101/2024.10.18.618948.
Polyproline motifs are essential structural features of many proteins, and recent evidence suggests that EF-P is one of several factors that facilitate their translation. For example, YfmR was recently identified as a protein that prevents ribosome stalling at proline-containing sequences in the absence of EF-P. Here, we show that the YebC-family protein YebC2 (formerly YeeI) functions as a translation factor in that resolves ribosome stalling at polyprolines. We demonstrate that YebC2, EF-P and YfmR act independently to support cellular fitness. Moreover, we show that YebC2 interacts directly with the 70S ribosome, supporting a direct role for YebC2 in translation. Finally, we assess the evolutionary relationship between YebC2 and other characterized YebC family proteins, and present evidence that transcription and translation factors within the YebC family have evolved separately. Altogether our work identifies YebC2 as a translation factor that resolves ribosome stalling and provides crucial insight into the relationship between YebC2, EF-P, and YfmR, three factors that prevent ribosome stalling at prolines.
多聚脯氨酸基序是许多蛋白质的重要结构特征，最近的证据表明，延伸因子P（EF-P）是促进其翻译的几个因子之一。例如，YfmR最近被鉴定为一种在缺乏EF-P时可防止核糖体在含脯氨酸序列处停滞的蛋白质。在此，我们表明YebC家族蛋白YebC2（以前称为YeeI）作为一种翻译因子，可解决核糖体在多聚脯氨酸处的停滞问题。我们证明YebC2、EF-P和YfmR独立发挥作用以维持细胞适应性。此外，我们表明YebC2直接与70S核糖体相互作用，支持YebC2在翻译中发挥直接作用。最后，我们评估了YebC2与其他已表征的YebC家族蛋白之间的进化关系，并提供证据表明YebC家族内的转录和翻译因子是独立进化的。总之，我们的工作确定YebC2为一种可解决核糖体停滞的翻译因子，并为YebC2、EF-P和YfmR这三个防止核糖体在脯氨酸处停滞的因子之间的关系提供了关键见解。
