Structural Basis for Domain–Domain Communication in a Protein Tyrosine Kinase, the C-terminal Src Kinase
| Autor: | Yue-Hao Wang, Gongqin Sun, Xiaofeng Lin, Keykavous Parang, Yousef Ahmadibeni |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Models
Molecular animal structures Recombinant Fusion Proteins Arginine Crystallography X-Ray Ligands SH2 domain medicine.disease_cause CSK Tyrosine-Protein Kinase src Homology Domains Structural Biology medicine Point Mutation Molecular Biology Mutation Tyrosine-protein kinase CSK Chemistry Tryptophan Protein-Tyrosine Kinases Ligand (biochemistry) Protein Structure Tertiary Cell biology Enzyme Activation src-Family Kinases Biochemistry Domain (ring theory) Tyrosine kinase Linker Protein Binding Proto-oncogene tyrosine-protein kinase Src |
| Zdroj: | Journal of Molecular Biology. 357:1263-1273 |
| ISSN: | 0022-2836 |
| DOI: | 10.1016/j.jmb.2006.01.046 |
| Popis: | The catalytic activity of protein tyrosine kinases is commonly regulated by domain-domain interactions. The C-terminal Src kinase (Csk) contains a catalytic domain and the regulatory SH3 and SH2 domains. Both the presence of the regulatory domains and binding of specific phosphotyrosine-containing proteins to the SH2 domain activate Csk. The structural basis for both modes of activation is investigated here. First, the SH3-SH2 linker is crucial for Csk activation. Mutagenic and kinetic studies demonstrate that this activation is mediated by a cation-pi interaction between Arg68 and Trp188. Second, Ala scanning and kinetic analyses on residues in the SH2-catalytic domain interface identify three functionally distinct types of residues in mediating the communication between the SH2 and the catalytic domains. Type I residues are important in mediating a ligand-triggered activation of Csk because their mutation severely reduces Csk activation by the SH2 domain ligand. Type II residues are involved in suppressing Csk activity, and their mutation activates Csk, but makes Csk less sensitive to activation by the SH2 ligand. Both type I and type II residues are likely involved in mediating SH2 ligand-triggered activation of Csk. Type III residues are those located in the SH2 domain whose mutation severely decreases Csk catalytic activity without affecting the SH2 ligand-triggered activation. These residues likely mediate SH2 activation of Csk regardless of SH2-ligand interaction. These studies lead us to propose a domain-domain communication model that provides functional insights into the topology of Csk family of protein tyrosine kinases. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect