Departamento de Química Física I, Universidad Complutense de Madrid, Ciudad Universitaria s/n, E28040 Madrid, Spain.
FASEB J. 2013 Aug;27(8):3363-75. doi: 10.1096/fj.12-224337. Epub 2013 May 9.
The full-length ZipA protein from Escherichia coli, one of the essential elements of the cell division machinery, was studied in a surface model built as adsorbed monolayers. The interplay between lateral packing and molecular conformation was probed using a combined methodology based on the scaling analysis of the surface pressure isotherms and ellipsometry measurements of the monolayer thickness. The observed behavior is compatible with the one expected for an intrinsically disordered and highly flexible protein that is preferentially structured in a random coil conformation. At low grafting densities, ZipA coils organize in a mushroom-like regime, whereas a coil-to-brush transition occurs on increasing lateral packing. The structural results suggest a functional scenario in which ZipA acts as a flexible tether anchoring bacterial proto-ring elements to the membrane during the earlier stages of division.
来自大肠杆菌的全长 ZipA 蛋白是细胞分裂机制的基本要素之一，在构建的表面模型中作为吸附单层进行了研究。使用基于表面压力等温线的标度分析和单层厚度的椭圆测量的组合方法，探测了侧部堆积和分子构象之间的相互作用。观察到的行为与预期的固有无序和高度灵活的蛋白质的行为兼容，该蛋白质优先以无规卷曲构象构象。在低接枝密度下，ZipA 线圈以蘑菇状状态组织，而在增加侧部堆积时则发生线圈到刷子的转变。结构结果表明了一种功能方案，其中 ZipA 作为柔性系绳在分裂的早期阶段将细菌原环元件锚定到膜上。
