Sevvana Madhumati, Biadene Marianna, Ma Qingjun, Guo Chaoshe, Söling Hans Dieter, Sheldrick George M, Ferrari David M
Lehrstuhl für Strukturchemie, Georg-August Universität, Tammanstrasse 4, D-37077 Göttingen, Germany.
Acta Crystallogr D Biol Crystallogr. 2006 Jun;62(Pt 6):589-94. doi: 10.1107/S0907444906010456. Epub 2006 May 12.
The structures of the PDI-related protein Wind (with a C-terminal His(6) tag) and the mutants Y53S, Y53F and Y55K have been determined and compared with the wild-type structure with the His(6) tag at the N-terminus. All five structures show the same mode of dimerization, showing that this was not an artefact introduced by the nearby N-terminal His(6) tag and suggesting that this dimer may also be the biologically active form. Although the mutants Y53S and Y55K completely abrogate transport of the protein Pipe (which appears to be the primary function of Wind in the cell), only subtle differences can be seen in the putative Pipe-binding region. The Pipe binding in the active forms appears to involve hydrophobic interactions between aromatic systems, whereas the inactive mutants may be able to bind more strongly with the help of hydrogen bonds, which could disturb the delicate equilibrium required for effective Pipe transport.
已确定与蛋白质二硫键异构酶（PDI）相关的蛋白质Wind（带有C端His(6)标签）及其突变体Y53S、Y53F和Y55K的结构，并与N端带有His(6)标签的野生型结构进行了比较。所有这五种结构都显示出相同的二聚化模式，这表明这不是由附近的N端His(6)标签引入的假象，并且表明这种二聚体也可能是生物活性形式。尽管突变体Y53S和Y55K完全消除了蛋白质Pipe的转运（这似乎是Wind在细胞中的主要功能），但在假定的Pipe结合区域仅能看到细微差异。活性形式中的Pipe结合似乎涉及芳香体系之间的疏水相互作用，而非活性突变体可能能够借助氢键更强烈地结合，这可能会扰乱有效转运Pipe所需的微妙平衡。
