Håkansson Maria, Linse Sara
Department of Clinical chemistry, Lund University, Wallenberg laboratory, University hospital Malmö, Malmö, Sweden.
Curr Protein Pept Sci. 2002 Dec;3(6):629-42. doi: 10.2174/1389203023380459.
The native structures of proteins are governed by a large number of non-covalent interactions yielding a high specificity for the native packing of structural elements. This allows for the reconstitution of proteins from disconnected polypeptide fragments. The specificity for the native arrangement also enables interchange of structural elements with another identical protein chain resulting in dimers with swapped segments. Proteins are not static structures, but open up repetitively on a timescale of minutes to years depending on the identity of the protein and solution conditions. The open protein may self-close and return to the native state, or it may close with another polypeptide chain leading to 3D domain swapping. The term describes two or more protein molecules swapping identical domains or smaller secondary structure elements. The non-covalent intra-molecular interactions between domains in the monomer are thus broken and restored in the oligomer by identical inter-molecular contacts. This review will discuss 3D domain swapping in relation to protein reconstitution and fibril formation. Examples of reconstituted and domain-swapped proteins will be given. The physiological benefits of 3D domain swapping will be discussed, as well as its role in the evolution of proteins and pathology.
蛋白质的天然结构由大量非共价相互作用决定，这些相互作用赋予结构元件天然组装高度的特异性。这使得蛋白质能够从分离的多肽片段中重构。天然排列的特异性还使得结构元件能够与另一条相同的蛋白质链进行交换，从而形成具有交换片段的二聚体。蛋白质并非静态结构，而是会根据蛋白质的特性和溶液条件，在数分钟到数年的时间尺度上反复打开。打开的蛋白质可能会自我闭合并回到天然状态，或者与另一条多肽链闭合，导致三维结构域交换。该术语描述的是两个或多个蛋白质分子交换相同的结构域或较小的二级结构元件。单体中结构域之间的非共价分子内相互作用因此在寡聚体中通过相同的分子间接触被打破并重新形成。本综述将讨论与蛋白质重构和纤维形成相关的三维结构域交换。将给出重构和结构域交换蛋白质的例子。还将讨论三维结构域交换的生理益处，以及它在蛋白质进化和病理学中的作用。
