Source:EPL (Europhysics Letters), 97:68003, 2012
Using a specifically designed Go-model we have performed all-atom simulations of the C-fragment of TOP7. Our results support previous results (see Mohanty S. et al. , Proc. Natl. Acad. Sci. U.S.A. , 105 (2008) 8004; Mohanty S. and Hansmann U. H. E., J. Phys. Chem. B , 112 (2008) 15134) that indicate folding of this protein through configurations with non-native secondary structure. The N-terminal residues form first an extension of a subsequent Î±-helix, before finally refolding into a Î²-strand that completes a three-stranded Î²-sheet in the final structure. We show that mutations which reduce the "chameleonicity" of N-terminal residues (by increasing the propensity for "strandness" and reducing that for "helicity") lead to folding into the same structure but with reduced folding rates and larger free-energy barriers.