Structural basis for the RING-catalyzed synthesis of K63-linked ubiquitin chains.
Structural basis for the RING-catalyzed synthesis of K63-linked ubiquitin chains.
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DOI：
10.1038/nsmb.3052
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发表时间：
2015-08
影响因子：
16.8
通讯作者：
Hay RT
中科院分区：
文献类型：
--
作者：
Branigan E;Plechanovová A;Jaffray EG;Naismith JH;Hay RT
RING E3 连接酶通过 Ube2V2-Ubc13 E2 复合物催化形成赖氨酸 63 连接的泛素链，这是许多重要生物过程所必需的。在这里，我们报道了大鼠 RNF4 的 RING 结构域二聚体与人 Ubc13~Ub 缀合物和 Ube2V2 复合物的结构。该结构捕获了与受体（引发）泛素结合的 Ube2V2，其 Lys63 的位置可能会导致对供体（第二个）泛素和 Ubc13 之间的连接的攻击，而 Ubc13 通过 RNF4 的 RING 结构域保持在活性“折回”构象中。通过定点突变体的体外泛素化测定验证了结构中确定的界面。这代表了 Lys63 连接的泛素链合成的第一个观点，其中底物泛素和负载泛素的 E2 并置以允许 E3 连接酶介导的催化。
The RING E3 ligase catalysed formation of lysine 63 linked ubiquitin chains by the Ube2V2–Ubc13 E2 complex is required for many important biological processes. Here we report the structure of the RING domain dimer of rat RNF4 in complex with a human Ubc13~Ub conjugate and Ube2V2. The structure has captured Ube2V2 bound to the acceptor (priming) ubiquitin with Lys63 in a position that could lead to attack on the linkage between the donor (second) ubiquitin and Ubc13 that is held in the active “folded back” conformation by the RING domain of RNF4. The interfaces identified in the structure were verified by in vitro ubiquitination assays of site directed mutants. This represents the first view of the synthesis of Lys63 linked ubiquitin chains in which both substrate ubiquitin and ubiquitin-loaded E2 are juxtaposed to allow E3 ligase mediated catalysis.