Escherichia coli transcription termination factor NusA: heat-induced oligomerization and chaperone activity.
Escherichia coli transcription termination factor NusA: heat-induced oligomerization and chaperone activity.
复制标题
DOI：
10.1038/srep02347
复制
发表时间：
2013
影响因子：
4.6
通讯作者：
Ma Y
中科院分区：
文献类型：
--
作者：
Li K;Jiang T;Yu B;Wang L;Gao C;Ma C;Xu P;Ma Y
大肠杆菌NusA是RNA聚合酶延伸复合物的重要组成部分，参与转录延伸、终止、抗终止、冷休克和胁迫诱导的突变。在这项研究中，我们证明了NusA可以在热休克条件下自组装成寡聚体，并且这种性质在很大程度上是由C-末端结构域决定的。在自组装过程的同时，NusA也获得了分子伴侣活性。此外，NusA过表达导致宿主细胞的热休克抗性增强，这可能是由于NusA的伴侣活性。我们的结果表明，E. coli NusA在体外和NusA过表达菌株中可以作为保护剂防止热应激条件下的蛋白质聚集。我们提出了一个新的假设，NusA可以作为一个分子伴侣，除了作为一个转录因子的功能。然而，NusA在正常生理条件下是否具有相同的功能还有待进一步研究。
Escherichia coli NusA, an essential component of the RNA polymerase elongation complex, is involved in transcriptional elongation, termination, anti-termination, cold shock and stress-induced mutagenesis. In this study, we demonstrated that NusA can self-assemble into oligomers under heat shock conditions and that this property is largely determined by the C-terminal domain. In parallel with the self-assembly process, NusA also acquires chaperone activity. Furthermore, NusA overexpression results in the enhanced heat shock resistance of host cells, which may be due to the chaperone activity of NusA. Our results suggest that E. coli NusA can act as a protector to prevent protein aggregation under heat stress conditions in vitro and in the NusA-overexpressing strain. We propose a new hypothesis that NusA could serve as a molecular chaperone in addition to its functions as a transcription factor. However, it remains to be further investigated whether NusA has the same function under normal physiological conditions.