Van Troys M, Dewitte D, Goethals M, Vandekerckhove J, Ampe C
Flanders Interuniversity Institute for Biotechnology, Department of Biochemistry, Faculty of Medicine, Universiteit Gent, Belgium.
FEBS Lett. 1996 Nov 18;397(2-3):191-6. doi: 10.1016/s0014-5793(96)01086-1.
Gelsolin is built up of six homologous segments that perform different functions on actin. Segments 1 and 2, which are suggested to be highly similar in their overall folds, bind monomeric and filamentous actin respectively. A long alpha-helix in segment 1 forms the major contact site of this segment with actin. We show that sequence 197-226 of segment 2, equivalent to the region around the actin binding helix in segment 1, contains F-actin binding activity. Consequently, positionally similar parts of segment 1 and 2 are implicated in the actin contact and solvent exposed residues in these parts must have evolved differentially to meet their different actin binding properties.
凝溶胶蛋白由六个同源片段组成，这些片段对肌动蛋白发挥不同功能。片段1和2在整体折叠上高度相似，分别结合单体肌动蛋白和丝状肌动蛋白。片段1中的一个长α螺旋形成了该片段与肌动蛋白的主要接触位点。我们发现，片段2的197 - 226序列，等同于片段1中肌动蛋白结合螺旋周围的区域，具有F - 肌动蛋白结合活性。因此，片段1和2中位置相似的部分与肌动蛋白接触有关，并且这些部分中暴露于溶剂的残基必定已经发生了不同的进化，以满足它们不同的肌动蛋白结合特性。
