Thermodynamics, kinetics, and salt dependence of folding of YopM, a large leucine-rich repeat protein.

ABSTRACT: Small globular proteins have many contacts between residues that are distant in primary sequence. These contacts create a complex network between sequence-distant segments of secondary structure, which may be expected to promote the cooperative folding of globular proteins. Although repeat proteins, which are composed of tandem modular units, lack sequence-distant contacts, several of considerable length have been shown to undergo cooperative two-state folding. To explore the limits of cooperativity in repeat proteins, we have studied the unfolding of YopM, a leucine-rich repeat (LRR) protein of over 400 residues. Despite its large size and modular architecture (15 repeats), YopM equilibrium unfolding is highly cooperative, and shows a very strong dependence on the concentration of urea. I

SUBMITTER: Kloss E 

PROVIDER: S-EPMC3204414 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature