Section of Molecular Microbiology, Department of Molecular Cell Biology, Vrije Universiteit, Amsterdam 1081 HV, Netherlands.
J Bacteriol. 2011 Oct;193(19):5242-51. doi: 10.1128/JB.05429-11. Epub 2011 Jul 29.
YidC has an essential but poorly defined function in membrane protein insertion and folding in bacteria. The yidC gene is located in a gene cluster that is highly conserved in Gram-negative bacteria, the gene order being rpmH, rnpA, yidD, yidC, and trmE. Here, we show that Escherichia coli yidD, which overlaps with rnpA and is only 2 bp upstream of yidC, is expressed and localizes to the inner membrane, probably through an amphipathic helix. Inactivation of yidD had no discernible effect on cell growth and viability. However, compared to control cells, ΔyidD cells were affected in the insertion and processing of three YidC-dependent inner membrane proteins. Furthermore, in vitro cross-linking showed that YidD is in proximity of a nascent inner membrane protein during its localization in the Sec-YidC translocon, suggesting that YidD might be involved in the insertion process.
YidC 在细菌中膜蛋白插入和折叠中具有重要但定义不明确的功能。yidC 基因位于革兰氏阴性细菌中高度保守的基因簇中，基因顺序为 rpmH、rnpA、yidD、yidC 和 trmE。在这里，我们表明大肠杆菌 yidD 与 rnpA 重叠，并且仅在 yidC 的上游 2bp 处，被表达并定位于内膜，可能通过两性螺旋。yidD 的失活对细胞生长和活力没有明显影响。然而，与对照细胞相比，ΔyidD 细胞在三种依赖 YidC 的内膜蛋白的插入和加工中受到影响。此外，体外交联显示 YidD 在其在 Sec-YidC 转运体中的定位过程中与新生内膜蛋白接近，表明 YidD 可能参与插入过程。
