Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA.
Proc Natl Acad Sci U S A. 2013 Jul 16;110(29):11815-20. doi: 10.1073/pnas.1303289110. Epub 2013 Jul 1.
We have established a reconstitution system for the translocon SecYEG in proteoliposomes in which 55% of the accessible translocons are active. This level corresponds to the fraction of translocons that are active in vitro when assessed in their native environment of cytoplasmic membrane vesicles. Assays using these robust reconstituted proteoliposomes and cytoplasmic membrane vesicles have revealed that the number of SecYEG units involved in an active translocase depends on the precursor undergoing transfer. The active translocase for the precursor of periplasmic galactose-binding protein contains twice the number of heterotrimeric units of SecYEG as does that for the precursor of outer membrane protein A.
我们已经建立了一个在脂蛋白体中重建 SecYEG 易位子的系统，其中 55%的可及易位子是活跃的。这个水平与在细胞质膜囊泡的天然环境中评估时体外活性易位子的分数相对应。使用这些稳健的重组脂蛋白体和细胞质膜囊泡的测定表明，参与活性转运体的 SecYEG 单位的数量取决于正在转移的前体。用于周质结合蛋白半乳糖前体的活性转运体含有两倍于外膜蛋白 A 前体的 SecYEG 异三聚体单位。
