Exclusively membrane-inserted state of an uncleavable Tat precursor protein suggests lateral transfer into the bilayer from the translocon.
Exclusively membrane-inserted state of an uncleavable Tat precursor protein suggests lateral transfer into the bilayer from the translocon.
复制标题
不可切割的 Tat 前体蛋白的完全膜插入状态表明从易位子横向转移到双层中。
DOI：
10.1111/febs.12327
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Ren C
中科院分区：
文献类型：
--
作者：
Ren C
在细菌中，通过双精氨酸移位酶（达特）途径输出蛋白质由可裂解的N末端信号肽指导。我们使用底物YedY研究了转运和成熟之间的关系，YedY在信号肽的-1位含有Ala > Leu取代。这阻碍了成熟，并导致膜结合前体形式的积累，成熟结构域暴露于周质。它的积累不阻断其他达特底物的转运，表明已经发生了从易位通道的退出，并且前体蛋白质被牢固地整合到膜双层中。前体的膜整合性质，以及周质中完全不存在前体蛋白，强烈表明前体在易位过程中已经侧向转移到双层中。我们建议，随后的蛋白水解加工释放成熟的蛋白质进入周质。处理的延迟导致细胞生长的抑制，强调了达特底物有效成熟的要求。
In bacteria, the export of proteins by the twin‐arginine translocase (Tat) pathway is directed by cleavable N‐terminal signal peptides. We studied the relationship between transport and maturation using a substrate, YedY, that contains an Ala > Leu substitution at the ‐1 position of the signal peptide. This blocks maturation and leads to the accumulation of a membrane‐bound precursor form with the mature domain exposed to the periplasm. Its accumulation does not block transport of other Tat substrates, indicating that exit from the translocation channel has taken place, and the precursor protein is fir mLy integrated into the membrane bilayer. The membrane‐integrated nature of the precursor, and complete absence of precursor protein in the periplasm, strongly suggest that the precursor has undergone lateral transfer into the bilayer during translocation. We propose that subsequent proteolytic processing releases the mature protein into the periplasm. A delay in processing results in an inhibition of cell growth, emphasizing a requirement for efficient maturation of Tat substrates.