Mizushima Tsunehiro, Tatsumi Kanako, Ozaki Yoko, Kawakami Tatsukuni, Suzuki Atsuo, Ogasahara Kyoko, Komatsu Masaaki, Kominami Eiki, Tanaka Keiji, Yamane Takashi
Department of Biotechnology, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan.
Biochem Biophys Res Commun. 2007 Nov 3;362(4):1079-84. doi: 10.1016/j.bbrc.2007.08.129. Epub 2007 Aug 30.
Ubiquitin and ubiquitin-like protein-conjugating enzymes play central roles in posttranslational modification processes. The ubiquitin-fold modifier 1 (Ufm1), one of a variety of ubiquitin-like modifiers, is covalently attached to target proteins via Uba5 and Ufm1-conjugating enzyme 1 (Ufc1), which are analogous to the E1 and E2 ubiquitylation enzymes. As Ufm1-related proteins are conserved in metazoa and plants, the Ufm1 system likely plays important roles in various multicellular organisms. Herein, we report the X-ray structure of human Ufc1 determined at 1.6 A resolution. The Ufc1 structure comprises a canonical E2 domain and an additional N-terminal domain. The Uba5 binding site on Ufc1 was assigned by structural comparison of Ufc1 and Ubc12 and related mutational analyses. In addition, we show that the N-terminal unique domain of Ufc1 contributes to thermal stability.
泛素和类泛素蛋白缀合酶在翻译后修饰过程中发挥核心作用。泛素样修饰因子1（Ufm1）是多种泛素样修饰因子之一，通过与E1和E2泛素化酶类似的Uba5和Ufm1缀合酶1（Ufc1）与靶蛋白共价连接。由于Ufm1相关蛋白在后生动物和植物中保守，Ufm1系统可能在各种多细胞生物中发挥重要作用。在此，我们报道了以1.6埃分辨率测定的人Ufc1的X射线结构。Ufc1结构包括一个典型的E2结构域和一个额外的N端结构域。通过Ufc1和Ubc12的结构比较及相关突变分析确定了Ufc1上的Uba5结合位点。此外，我们表明Ufc1的N端独特结构域有助于热稳定性。
