4F59

Triple mutant Src SH2 domain

4F59 の概要

• エントリーDOI: 10.2210/pdb4f59/pdb
• 関連するPDBエントリー: 4F5A 4F5B
• 分子名称: Proto-oncogene tyrosine-protein kinase Src (2 entities in total)
• 機能のキーワード: sh2 domain, cell signalling, phosphotyrosine binding, protein binding
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Cell membrane: P12931
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 12699.32

構造登録者

Kaneko, T.,Huang, H.,Cao, X.,Li, C.,Voss, C.,Sidhu, S.S.,Li, S.S. (登録日: 2012-05-12, 公開日: 2012-10-03, 最終更新日: 2024-02-28)

主引用文献

Kaneko, T.,Huang, H.,Cao, X.,Li, X.,Li, C.,Voss, C.,Sidhu, S.S.,Li, S.S.
Superbinder SH2 Domains Act as Antagonists of Cell Signaling.
Sci.Signal., 5:ra68-ra68, 2012

PubMed Abstract: Protein-ligand interactions mediated by modular domains, which often play important roles in regulating cellular functions, are generally of moderate affinities. We examined the Src homology 2 (SH2) domain, a modular domain that recognizes phosphorylated tyrosine (pTyr) residues, to investigate how the binding affinity of a modular domain for its ligand influences the structure and cellular function of the protein. We used the phage display method to perform directed evolution of the pTyr-binding residues in the SH2 domain of the tyrosine kinase Fyn and identified three amino acid substitutions that critically affected binding. We generated three SH2 domain triple-point mutants that were "superbinders" with much higher affinities for pTyr-containing peptides than the natural domain. Crystallographic analysis of one of these superbinders revealed that the superbinder SH2 domain recognized the pTyr moiety in a bipartite binding mode: A hydrophobic surface encompassed the phenyl ring, and a positively charged site engaged the phosphate. When expressed in mammalian cells, the superbinder SH2 domains blocked epidermal growth factor receptor signaling and inhibited anchorage-independent cell proliferation, suggesting that pTyr superbinders might be explored for therapeutic applications and useful as biological research tools. Although the SH2 domain fold can support much higher affinity for its ligand than is observed in nature, our results suggest that natural SH2 domains are not optimized for ligand binding but for specificity and flexibility, which are likely properties important for their function in signaling and regulatory processes.

PubMed: 23012655
DOI: 10.1126/scisignal.2003021

実験手法

X-RAY DIFFRACTION (1.71 Å)