Putney D Reid, Todd Emily A, Berndsen Christopher E, Wright Nathan T
Department of Chemistry and Biochemistry, James Madison University, 901 Carrier Dr., Harrisonburg, VA, 22807, USA.
Biomol NMR Assign. 2015 Oct;9(2):407-10. doi: 10.1007/s12104-015-9619-x. Epub 2015 May 7.
The ubiquitination pathway controls several human cellular processes, most notably protein degradation. Ubiquitin, a small signaling protein, is activated by the E1 activating enzyme, transferred to an E2 conjugating enzyme, and then attached to a target substrate through a process that can be facilitated by an E3 ligase enzyme. The enzymatic mechanism of ubiquitin transfer from the E2 conjugating enzyme onto substrate is not clear. The highly conserved HPN motif in E2 catalytic domains is generally thought to help stabilize an oxyanion intermediate formed during ubiquitin transfer. However recent work suggests this motif is instead involved in a structural, non-enzymatic role. As a platform to better understand the E2 catalyzed ubiquitin transfer mechanism, we determined the chemical shift assignments of S. cerevisiae E2 enzyme Ubc13.
泛素化途径控制着多种人类细胞过程，最显著的是蛋白质降解。泛素是一种小信号蛋白，由E1激活酶激活，转移至E2缀合酶，然后通过E3连接酶促进的过程附着于目标底物。泛素从E2缀合酶转移到底物上的酶促机制尚不清楚。E2催化结构域中高度保守的HPN基序通常被认为有助于稳定泛素转移过程中形成的氧阴离子中间体。然而，最近的研究表明，该基序反而参与了一种结构性的非酶促作用。作为一个更好地理解E2催化泛素转移机制的平台，我们确定了酿酒酵母E2酶Ubc13的化学位移归属。
