Ohno Ayako, Jee JunGoo, Fujiwara Kenichiro, Tenno Takeshi, Goda Natsuko, Tochio Hidehito, Kobayashi Hideki, Hiroaki Hidekazu, Shirakawa Masahiro
Graduate School of Integrated Science, Yokohama City University, Yokohama, Kanagawa 230-0045, Japan.
Structure. 2005 Apr;13(4):521-32. doi: 10.1016/j.str.2005.01.011.
The ubiquitin-associated (UBA) domain is one of the most frequently occurring motifs that recognize ubiquitin tags. Dsk2p, a UBA-containing protein from Saccharomyces cerevisiae, is involved in the ubiquitin-proteasome proteolytic pathway and has been implicated in spindle pole duplication. Here we present the solution structure of the UBA domain of Dsk2p (Dsk2(UBA)) in complex with ubiquitin. The structure reveals that the UBA domain uses a mode of ubiquitin recognition that is similar to that of the CUE domain, another ubiquitin binding motif that shares low sequence homology but high structural similarity with UBA domains. These two domains, as well as the structurally unrelated ubiquitin binding motif UIM, provide a common, crucial recognition site for ubiquitin, comprising a hydrogen-bonding acceptor for the amide group of Gly-47, and a methyl group that packs against the hydrophobic pocket of ubiquitin formed by Leu-8, Ile-44, His-68, and Val-70.
泛素相关（UBA）结构域是识别泛素标签的最常见基序之一。Dsk2p是一种来自酿酒酵母的含UBA结构域的蛋白质，参与泛素-蛋白酶体蛋白水解途径，并与纺锤极体复制有关。本文展示了与泛素结合的Dsk2p的UBA结构域（Dsk2(UBA)）的溶液结构。该结构表明，UBA结构域采用的泛素识别模式与CUE结构域相似，CUE结构域是另一种泛素结合基序，与UBA结构域序列同源性低但结构相似性高。这两个结构域，以及结构上不相关的泛素结合基序UIM，为泛素提供了一个共同的关键识别位点，包括一个与Gly-47酰胺基团形成氢键的受体，以及一个与由Leu-8、Ile-44、His-68和Val-70形成的泛素疏水口袋紧密堆积的甲基。
