Using FlAsH to probe conformational changes in a large HEAT repeat protein.

TitleUsing FlAsH to probe conformational changes in a large HEAT repeat protein.
Publication TypeJournal Article
Year of Publication2012
AuthorsTsytlonok, M., and L. S. Itzhaki
JournalChembiochem
Volume13
Issue8
Pagination1199-205
Date Published2012 May 29
ISSN1439-7633
KeywordsAmino Acid Sequence, Binding Sites, Cysteine, Fluorescent Dyes, Nuclear Proteins, Protein Conformation, Spectrometry, Fluorescence, Tandem Repeat Sequences
Abstract

We have investigated the use of FlAsH, a small fluorogenic molecule that binds to tetracysteine motifs, to probe folding of the 15-HEAT repeat protein PR65A. PR65A is one of a special class of modular non-globular proteins known as tandem repeat proteins, which are composed of small structural motifs that stack to form elongated, one-dimensional architectures. We were able to introduce linear and bipartite tetracysteine motifs at several sites along the α-helical HEAT array of PR65A without disrupting the structure or stability. When the linear tetracysteine motif CCPGCC was used, FlAsH fluorescence reported globally on the folding of the protein. When the tetracysteine motif was displayed in bipartite mode through the engineering of pairs of cysteines on adjacent HEAT repeats, FlAsH fluorescence became a reporter of local conformation and of oligomerisation. Thus, by designing FlAsH-binding sites at different locations along the repeat array one can interrogate specific properties of PR65A, paving the way for structure-function analysis of this protein both in vitro and in the cell.

DOI10.1002/cbic.201200012
Alternate JournalChembiochem
PubMed ID22539214
Grant ListG1002329 / / Medical Research Council / United Kingdom
Research group: