3VGO

Crystal structure of the N-terminal fragment of Cbl-b

3VGO の概要

• エントリーDOI: 10.2210/pdb3vgo/pdb
• 分子名称: E3 ubiquitin-protein ligase CBL-B (1 entity in total)
• 機能のキーワード: merohedral twinning, e3 ligase, ligase
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Cytoplasm: Q13191
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 136914.89

構造登録者

Kobashigawa, Y.,Noda, N.N.,Inagaki, F. (登録日: 2011-08-18, 公開日: 2011-12-14, 最終更新日: 2023-11-08)

主引用文献

Kobashigawa, Y.,Tomitaka, A.,Kumeta, H.,Noda, N.N.,Yamaguchi, M.,Inagaki, F.
Autoinhibition and phosphorylation-induced activation mechanisms of human cancer and autoimmune disease-related E3 protein Cbl-b
Proc.Natl.Acad.Sci.USA, 108:20579-20584, 2011

PubMed Abstract: Cbl-b is a RING-type E3 ubiquitin ligase that functions as a negative regulator of T-cell activation and growth factor receptor and nonreceptor-type tyrosine kinase signaling. Cbl-b dysfunction is related to autoimmune diseases and cancers in humans. However, the molecular mechanism regulating its E3 activity is largely unknown. NMR and small-angle X-ray scattering analyses revealed that the unphosphorylated N-terminal region of Cbl-b forms a compact structure by an intramolecular interaction, which masks the interaction surface of the RING domain with an E2 ubiquitin-conjugating enzyme. Phosphorylation of Y363, located in the helix-linker region between the tyrosine kinase binding and the RING domains, disrupts the interdomain interaction to expose the E2 binding surface of the RING domain. Structural analysis revealed that the phosphorylated helix-RING region forms a compact structure in solution. Moreover, the phosphate group of pY363 is located in the vicinity of the interaction surface with UbcH5B to increase affinity by reducing their electrostatic repulsion. Thus, the phosphorylation of Y363 regulates the E3 activity of Cbl-b by two mechanisms: one is to remove the masking of the RING domain from the tyrosine kinase binding domain and the other is to form a surface to enhance binding affinity to E2.

PubMed: 22158902
DOI: 10.1073/pnas.1110712108

実験手法

X-RAY DIFFRACTION (3.1 Å)