Biochemical and structural characterization of a novel ubiquitin-conjugating enzyme E2 from Agrocybe aegeria reveals Ube2w family-specific properties.
Biochemical and structural characterization of a novel ubiquitin-conjugating enzyme E2 from Agrocybe aegeria reveals Ube2w family-specific properties.
复制标题
来自 Agrocybe aegeria 的新型泛素结合酶 E2 的生化和结构表征揭示了 Ube2w 家族特有的特性。
DOI：
10.1038/srep16056
复制
发表时间：
2015-11-03
影响因子：
4.6
通讯作者：
Liu W
中科院分区：
文献类型：
--
作者：
Qi C;Li DF;Feng L;Hou Y;Sun H;Wang DC;Liu W
泛素化是一种翻译后修饰，涉及多种细胞调节和疾病途径。泛素结合酶 (E2) 是泛素转移途径中的重要参与者。尽管有许多 E2 结构可用，但并非所有 E2 家族都有已知的结构，并且缺乏来自酵母以外的真菌生物体的三维结构。我们在这里报道了 UbcA1 的晶体结构，它是一种从食用和药用蘑菇 Agrocybe aegerita 中鉴定出的新型泛素结合酶，具有潜在的抗肿瘤特性。该蛋白属于 Ube2w 家族，表现出与人类 Ube2w 相似的生化特征，包括溶液中的单体-二聚体平衡、α-NH2 泛素转移活性以及识别底物中本质无序 N 末端骨架原子的机制。其结构显示出独特的 C 端构象，其螺旋 α3 的方向与报道的 E2 结构完全不同，但与最近报道的 Ube2w NMR 系综相似。对这种新型酶的诱变研究表明，完整的 C 末端对于蛋白质二聚化和酶活性具有重要意义。作为该家族第一个结晶的全长蛋白，UbcA1可能会取代Ube2w的截短X射线结构（PDB条目2A7L）成为Ube2w家族的代表结构。
Ubiquitination is a post-translational modification that is involved in myriad cellar regulation and disease pathways. The ubiquitin-conjugating enzyme (E2) is an important player in the ubiquitin transfer pathway. Although many E2 structures are available, not all E2 families have known structures and three-dimensional structures from fungal organisms other than yeast are lacking. We report here the crystal structure of UbcA1, which is a novel ubiquitin-conjugating enzyme identified from the edible and medicinal mushroom Agrocybe aegerita and displays potential antitumor properties. The protein belongs to the Ube2w family and shows similar biochemical characteristics to human Ube2w, including monomer-dimer equilibrium in solution, α-NH2 ubiquitin-transfer activity and a mechanism to recognize backbone atoms of intrinsically disordered N-termini in substrates. Its structure displays a unique C-terminal conformation with an orientation of helix α3 that is completely different from the reported E2 structures but similar to a recently reported NMR ensemble of Ube2w. A mutagenesis study on this novel enzyme revealed that an intact C-terminus is significant for protein dimerization and enzymatic activity. As the first crystallized full-length protein of this family, UbcA1 may supersede the truncated X-ray structure of Ube2w (PDB entry 2A7L) as the representative structure of the Ube2w family.