Open AccessEngineering a two-helix bundle protein for folding studies
Author(s) -
Charlotte A. Dodson,
Neil Ferguson,
Trevor J. Rutherford,
Christopher M. Johnson,
Alan R. Fersht
Publication year - 2010
Publication title -
protein engineering, design and selection
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.627
H-Index - 109
eISSN - 1741-0134
pISSN - 1741-0126
DOI - 10.1093/protein/gzp080
Subject(s) - phi value analysis , protein folding , folding (dsp implementation) , chemistry , lattice protein , crystallography , mutant , helix (gastropod) , downhill folding , protein engineering , helix bundle , saccharomyces cerevisiae , biophysics , protein design , protein structure , biochemistry , biology , yeast , ecology , electrical engineering , gene , enzyme , engineering , snail
The SAP domain from the Saccharomyces cerevisiae THO1 protein contains a hydrophobic core and just two alpha-helices. It could provide a system for studying protein folding that bridges the gap between studies on isolated helices and those on larger protein domains. We have engineered the SAP domain for protein folding studies by inserting a tryptophan residue into the hydrophobic core (L31W) and solved its structure. The helical regions had a backbone root mean-squared deviation of 0.9 A from those of wild type. The mutation L31W destabilised wild type by 0.8 +/- 0.1 kcal mol(-1). The mutant folded in a reversible, apparent two-state manner with a microscopic folding rate constant of around 3700 s(-1) and is suitable for extended studies of folding.