Surface salt bridges stabilize the GCN4 leucine zipper
| Autor: | Erik J. Spek, Min Lu, Au H. Bui, Neville R. Kallenbach |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Circular dichroism
Leucine zipper Hot Temperature Saccharomyces cerevisiae Proteins Dimer Molecular Sequence Data Static Electricity Biochemistry Fungal Proteins Structure-Activity Relationship chemistry.chemical_compound Protein structure Drug Stability Escherichia coli Amino Acid Sequence Structural motif Molecular Biology Leucine Zippers Fungal protein Alanine Chemistry Circular Dichroism Recombinant Proteins Protein Structure Tertiary DNA-Binding Proteins Crystallography Helix Mutagenesis Site-Directed Thermodynamics Salts Salt bridge Protein Kinases Research Article |
| Zdroj: | Protein Science. 7:2431-2437 |
| ISSN: | 1469-896X 0961-8368 |
| DOI: | 10.1002/pro.5560071121 |
| Popis: | We present a study of the role of salt bridges in stabilizing a simplified tertiary structural motif, the coiled-coil. Changes in GCN4 sequence have been engineered that introduce trial patterns of single and multiple salt bridges at solvent exposed sites. At the same sites, a set of alanine mutants was generated to provide a reference for thermodynamic analysis of the salt bridges. Introduction of three alanines stabilizes the dimer by 1.1 kcal/mol relative to the wild-type. An arrangement corresponding to a complex type of salt bridge involving three groups stabilizes the dimer by 1.7 kcal/ mol, an apparent elevation of the melting temperature relative to wild type of about 22 degrees C. While identifying local from nonlocal contributions to protein stability is difficult, stabilizing interactions can be identified by use of cycles. Introduction of alanines for side chains of lower helix propensity and complex salt bridges both stabilize the coiled-coil, so that combining the two should yield melting temperatures substantially higher than the starting species, approaching those of thermophilic sequences. |
| Databáze: | OpenAIRE |
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