Engineered diubiquitin synthesis reveals Lys29-isopeptide specificity of an OTU deubiquitinase
Engineered diubiquitin synthesis reveals Lys29-isopeptide specificity of an OTU deubiquitinase
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DOI：
10.1038/nchembio.426
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发表时间：
2010-10-01
影响因子：
14.8
通讯作者：
Chin, Jason W.
中科院分区：
文献类型：
--
作者：
Virdee, Satpal;Ye, Yu;Chin, Jason W.
泛素化是一种可逆的翻译后修饰，调节着真核生物的多种功能。我们研究泛素化效应的能力常常受到无法获得均匀泛素化蛋白质的限制。特别是，阐明所谓的“非典型”泛素链（Lys48或Lys63连接的泛素以外的链）的作用是具有挑战性的，因为它们的生物合成酶是未知的。在这里，我们结合联合收割机遗传密码扩展，内含肽化学和化学选择性连接合成“非典型”泛素链。我们解决了Lys6连接的双泛素的晶体结构，这是不同的结构特征的泛素链，提供了不同的生物学功能的分子基础，这种联系可能会调节。此外，我们分析了一组含有10%的已知人类去泛素化酶的Lys6和Lys29连接的泛素，并发现TRABID切割Lys29连接比Lys63连接有效40倍。
Ubiquitination is a reversible post-translational modification that regulates a myriad of eukaryotic functions. Our ability to study the effects of ubiquitination is often limited by the inaccessibility of homogeneously ubiquitinated proteins. In particular, elucidating the roles of the so-called 'atypical' ubiquitin chains (chains other than Lys48- or Lys63-linked ubiquitin), which account for a large fraction of ubiquitin polymers, is challenging because the enzymes for their biosynthesis are unknown. Here we combine genetic code expansion, intein chemistry and chemoselective ligations to synthesize 'atypical' ubiquitin chains. We solve the crystal structure of Lys6-linked diubiquitin, which is distinct from that of structurally characterized ubiquitin chains, providing a molecular basis for the different biological functions this linkage may regulate. Moreover, we profile a panel containing 10% of the known human deubiquitinases on Lys6- and Lys29-linked ubiquitin and discover that TRABID cleaves the Lys29 linkage 40-fold more efficiently than the Lys63 linkage.