CRYSTALLOGRAPHY OF HETEROTRIMERIC G PROTEIN COMPLEXES W/ REGULATORS & EFFECTORS

具有调节剂的异三聚 G 蛋白复合物的晶体学

• 批准号: 6667822
• 负责人: Stephen R Sprang
• 金额: $ 14.27万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-30 至 2003-08-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6667822
• 关键词: bioimaging /biomedical imaging; biological products; biomedical resource; proteins; radiography; structural biology

Data collected at MacCHESS under express mode proposal EM188 were used in the structure determination of the DPC4 and retinoblastoma (Rb) tumor suppressor proteins. DPC4 (now also known as Smad4) signals from TGFb superfamily receptor Ser/Thr protein kinases at the cell surface to the nucleus through homo- and hetero-oligomeric interactions. The crystal structure of the C-terminal domain (CTD) of DPC4, determined at 2.0
resolution, revelas that the DPC4-CTD forms a crystallographic trimer through a conserved protein-protein interface to which the majority of the tumor-derived missense mutations map. We showed that these mutations disrupt homo-oligomerization in vitro and in vivo, and suggested the hypothesis that the trimeric assembly of the Smad4/DPC4-CTD is a critical function in signaling that is targeted by tumorigenic mutations. Because our paper describing the DPC4 structure (1) went in press while we were collecting data at MacCHESS, it only describes a 2.5
-refined structure. The coordinates submitted to the Brookhaven Protein Data Bank were refined using the 2.0
data collected at MacCHESS. The retinoblastoma tumor suppressor, which in most human cancers is inactivated by mutations, is instead inactivated by the human papilloma virus E7 oncoprotein in cervical cancer. The crystal structure of Rb bound to a nine residue E7 peptide containing the LxCxE motif, shared by other Rb-bidning viral and cellular proteins, was determined at 1.85
resolution (2). The structure shows that the LxCxE peptide binds a highly conserved groove on the B box or the interface with the A box, which the structure shows is required for the stable folding of the B box.

在快速模式提案 EM188 下在 MacCHESS 收集的数据是 用于 DPC4 和视网膜母细胞瘤的结构测定 (Rb) 肿瘤抑制蛋白。 DPC4（现在也称为 Smad4） 来自 TGFb 超家族受体 Ser/Thr 蛋白激酶的信号 细胞表面通过同源和异源寡聚体到达细胞核 互动。 C端结构域（CTD）的晶体结构 DPC4，以 2.0 分辨率测定，表明 DPC4-CTD 形成 通过保守的蛋白质-蛋白质形成晶体三聚体 大多数肿瘤源性错义的界面 突变图。 我们证明这些突变会破坏 体外和体内同源寡聚化，并提出 假设 Smad4/DPC4-CTD 的三聚体组装是 致瘤性靶向信号传导中的关键功能 突变。 因为我们描述 DPC4 结构的论文 (1) 去了 当我们在 MacCHESS 收集数据时，它仅描述了 2.5 细化结构。 提交给布鲁克海文的坐标 蛋白质数据库使用收集的 2.0 数据进行了完善 麦克切斯。 视网膜母细胞瘤肿瘤抑制因子，在大多数人类中 癌症因突变而失活，而是因 宫颈癌中的人乳头瘤病毒 E7 癌蛋白。 水晶 Rb 与九个残基 E7 肽结合的结构，其中包含 LxCxE 基序，与其他 Rb 结合病毒和细胞蛋白共享， 分辨率为 1.85 (2)。 该结构表明 LxCxE 肽结合 B 盒或 与 A 盒的接口，结构显示这是必需的 B盒折叠稳定。