The role of a beta-bulge in the folding of the beta-hairpin structure in ubiquitin.


Abstract

It is known that the peptide corresponding to the N-terminal beta-hairpin of ubiquitin, U(1-17), can populate the monomeric beta-hairpin conformation in aqueous solution. In this study, we show that the Gly-10 that forms the bulge of the beta-turn in this hairpin is very important to the stability of the hairpin. The deletion of this residue to desG10(1-16) unfolds the structure of the peptide in water. Even under denaturing conditions, this bulge appears to be important in maintaining the residual structure of ubiquitin, which involves tertiary interactions within the sequence 1 to 34 in the denatured state. We surmise that this residual structure functions as one of the nucleation centers in the folding process and is important in stabilizing the transition state. In accordance with this idea, deleting Gly-10 slows down the refolding and unfolding rate by about one half. Study holds ProTherm entries: 12079, 12080 Extra Details: ubiquitin; hairpin; bulge; turn; peptide; structure; folding; stability; kinetics

Submission Details

ID: ZdPgXVfV3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:43 p.m.

Version: 1

Publication Details
Chen PY;Gopalacushina BG;Yang CC;Chan SI;Evans PA,Protein Sci. (2001) The role of a beta-bulge in the folding of the beta-hairpin structure in ubiquitin. PMID:11567097
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