The actin binding site of thymosin beta 4 mapped by mutational analysis
| Autor: | M F Carlier, Daisy Dewitte, Christophe Ampe, M. Van Troys, Joël Vandekerckhove, M Goethals |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1996 |
| Předmět: |
Circular dichroism
Molecular Sequence Data macromolecular substances Binding Competitive General Biochemistry Genetics and Molecular Biology Protein Structure Secondary Protein structure Animals Humans Actin-binding protein Amino Acid Sequence Binding site Muscle Skeletal Molecular Biology Peptide sequence Actin Conserved Sequence Binding Sites General Immunology and Microbiology biology Sequence Homology Amino Acid General Neuroscience Circular Dichroism Calcium-Binding Proteins Microfilament Proteins Genetic Variation Membrane Proteins Blood Proteins Phosphoproteins Actins Peptide Fragments Recombinant Proteins Thymosin beta-4 Thymosin Kinetics Cross-Linking Reagents Biochemistry biology.protein Biophysics Mutagenesis Site-Directed Rabbits Villin Carrier Proteins Chickens Research Article |
| Popis: | We characterized in detail the actin binding site of the small actin-sequestering protein thymosin beta 4 (T beta 4) using chemically synthesized full-length T beta 4 variants. The N-terminal part (residues 1-16) and a hexapeptide motif (residues 17-22) form separate structural entities. In both, we identified charged and hydrophobic residues that participate in the actin interaction using chemical cross-linking, complex formation in native gels and actin-sequestering experiments. Quantitative data on the activity of the variants and circular dichroism experiments allow to present a model in which the N-terminal part needs to adopt an alpha-helix for actin binding and interacts through a patch of hydrophobic residues (6M-I-F12) on one side of this helix. Also, electrostatic contacts between actin and lysine residues 18, in the motif, and 14, in the N-terminal alpha-helix, appear important for binding. The residues critical for contacting actin are conserved throughout the beta-thymosin family and in addition to this we identify a similar pattern in the C-terminal headpiece of villin and dematin. |
| Databáze: | OpenAIRE |
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