Elkins Jonathan M, Papagrigoriou Evangelos, Berridge Georgina, Yang Xiaowen, Phillips Claire, Gileadi Carina, Savitsky Pavel, Doyle Declan A
Structural Genomics Consortium, Oxford University, Botnar Research Centre, Oxford, OX3 7LD, United Kingdom.
Protein Sci. 2007 Apr;16(4):683-94. doi: 10.1110/ps.062657507.
PDZ domains are protein-protein interaction modules that generally bind to the C termini of their target proteins. The C-terminal four amino acids of a prospective binding partner of a PDZ domain are typically the determinants of binding specificity. In an effort to determine the structures of a number of PDZ domains we have included appropriate four residue extensions on the C termini of PDZ domain truncation mutants, designed for self-binding. Multiple truncations of each PDZ domain were generated. The four residue extensions, which represent known specificity sequences of the target PDZ domains and cover both class I and II motifs, form intermolecular contacts in the expected manner for the interactions of PDZ domains with protein C termini for both classes. We present the structures of eight unique PDZ domains crystallized using this approach and focus on four which provide information on selectivity (PICK1 and the third PDZ domain of DLG2), binding site flexibility (the third PDZ domain of MPDZ), and peptide-domain interactions (MPDZ 12th PDZ domain). Analysis of our results shows a clear improvement in the chances of obtaining PDZ domain crystals by using this approach compared to similar truncations of the PDZ domains without the C-terminal four residue extensions.
PDZ结构域是蛋白质-蛋白质相互作用模块，通常与其靶蛋白的C末端结合。PDZ结构域潜在结合伴侣的C末端四个氨基酸通常是结合特异性的决定因素。为了确定多个PDZ结构域的结构，我们在用于自结合的PDZ结构域截短突变体的C末端包含了合适的四个残基延伸。每个PDZ结构域都产生了多个截短形式。这四个残基延伸代表了靶PDZ结构域的已知特异性序列，涵盖了I类和II类基序，以预期的方式形成分子间接触，用于两类PDZ结构域与蛋白质C末端的相互作用。我们展示了使用这种方法结晶的八个独特PDZ结构域的结构，并重点关注四个结构域，它们提供了关于选择性（PICK1和DLG2的第三个PDZ结构域）、结合位点灵活性（MPDZ的第三个PDZ结构域）和肽-结构域相互作用（MPDZ的第12个PDZ结构域）的信息。对我们结果的分析表明，与没有C末端四个残基延伸的PDZ结构域类似截短形式相比，使用这种方法获得PDZ结构域晶体的机会有了明显提高。
