Analysis of electrostatic contributions to the selectivity of interactions between RING-finger domains and ubiquitin-conjugating enzymes
Analysis of electrostatic contributions to the selectivity of interactions between RING-finger domains and ubiquitin-conjugating enzymes
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DOI：
10.1002/prot.22120
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发表时间：
2009-01-01
影响因子：
2.9
通讯作者：
Thomson, Timothy M.
中科院分区：
文献类型：
--
作者：
Scheper, Johanna;Oliva, Baldo;Thomson, Timothy M.
被称为环指结构域的锌配位蛋白基序存在于一类泛素连接酶（E3）上，募集泛素缀合酶（E2），将它们拴在底物蛋白上以与泛素共价修饰。每个环指结构域可以募集不同的E2，并且这些相互作用通常是选择性的，因为某些环指结构域优先与某些E2结合。这种选择性获得特定的生物相关性时，招募E2发挥专门的功能。我们已经探索了确定两个环指结构域（RNF11和RNF103上的结构域）和两个E2（UBC13，一种通过泛素的Lys63催化泛素链延伸的专门E2）之间存在或不存在实验可检测的相互作用的决定因素，以及UbcH7，其通过Lys48介导多泛素化。通过迭代使用的计算预测工具和实验验证，我们已经发现，这些相互作用和它们的选择性部分地由静电相互作用连接的接触界面的特定残基的组合。我们的分析还预测，这些相互作用的选择性的主要决定因素驻留在环指结构域，而不是E2。应用这些规则的相互作用的选择性，使我们能够实验操纵的环指结构域E2对的相互作用的选择性的研究。
The zinc-coordinated protein motifs known as RING-finger domains, present on a class of ubiquitin ligases (E3's), recruit ubiquitin-conjugating enzymes (E2s), tethering them to substrate proteins for covalent modification with ubiquitin. Each RING-finger domain can recruit different E2s, and these interactions are frequently selective, in that certain RING-finger domains associate preferentially with certain E2s. This selectivity acquires particular biological relevance when the recruited E2s exert specialized functions. We have explored the determinants that specify the presence or absence of experimentally detectable interaction between two RING-finger domains, those on RNF11 and RNF103, and two E2s, UBC13, a specialized E2 that catalyzes ubiquitin chain elongation through Lys63 of ubiquitin, and UbcH7, which mediates polyubiquitylation through Lys48. Through the iterative use of computational predictive tools and experimental validations, we have found that these interactions and their selectivity are partly governed by the combinations of electrostatic interactions linking specific residues of the contact interfaces. Our analysis also predicts that the main determinants of selectivity of these interactions reside on the RING-finger domains, rather than on the E2s. The application of some of these rules of interaction selectivity has permitted us to experimentally manipulate the selectivity of interaction of the RING-finger domain-E2 pairs under study.