Kol Stefan, Nouwen Nico, Driessen Arnold J M
Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute and the Zernike Institute of Advanced Materials, University of Groningen, Haren, The Netherlands.
J Biol Chem. 2008 Apr 11;283(15):9871-7. doi: 10.1074/jbc.M709408200. Epub 2008 Feb 14.
YidC is a member of the Oxa1 family of proteins that facilitates the membrane insertion of a subset of inner membrane proteins in Escherichia coli. YidC acts as an insertase for membrane insertion of subunit c of the F(1)F(0) ATP synthase (F(0)c), but the requirements for substrate recognition have remained unclear. Here, we have analyzed the role of the charged aminoacyl residues in F(0)c in YidC targeting and membrane insertion. Binding experiments demonstrate that F(0)c is targeted directly to YidC without the presence of a stable lipid surface-bound intermediate. Positive charges in the cytoplasmic loop of F(0)c are important determinants for YidC binding and subsequent membrane insertion. These data support a model in which F(0)c binds directly to YidC prior to its membrane insertion.
YidC是促进大肠杆菌内膜蛋白亚群进行膜插入的Oxa1蛋白家族成员。YidC作为F(1)F(0) ATP合酶（F(0)c）亚基c膜插入的插入酶，但底物识别的要求仍不清楚。在此，我们分析了F(0)c中带电荷的氨酰基残基在YidC靶向和膜插入中的作用。结合实验表明，F(0)c在没有稳定的脂质表面结合中间体的情况下直接靶向YidC。F(0)c胞质环中的正电荷是YidC结合及随后膜插入的重要决定因素。这些数据支持了一种模型，即F(0)c在其膜插入之前直接与YidC结合。
