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Article
The Dual-Basin Landscape in GFP Folding
Proceedings Of The National Academy Of Sciences
  • Benjamin T. Andrews
  • Shachi Gosavi
  • John M. Finke, University of Washington Tacoma
  • José N. Onuchic, University of California San Diego
  • Patricia A. Jennings, University of California San Diego
Publication Date
8-26-2008
Document Type
Article
Abstract

Recent experimental studies suggest that the mature GFP has an unconventional landscape composed of an early folding event with a typical funneled landscape, followed by a very slow search and rearrangement step into the locked, active chromophore-containing structure. As we have shown previously, the substantial difference in time scales is what generates the observed hysteresis in thermodynamic folding. The interconversion between locked and the soft folding structures at intermediate denaturant concentrations is so slow that it is not observed under the typical experimental observation time. Simulations of a coarse-grained model were used to describe the fast folding event as well as identify native-like intermediates on energy landscapes enroute to the fluorescent native fold. Interestingly, these simulations reveal structural features of the slow dynamic transition to chromophore activation. Experimental evidence presented here shows that the trapped, native-like intermediate has structural heterogeneity in residues previously linked to chromophore formation. We propose that the final step of GFP folding is a "locking" mechanism leading to chromophore formation and high stability. The combination of previous experimental work and current simulation work is explained in the context of a dual-basin folding mechanism described above.

DOI
10.1073/pnas.0804039105
Version
pre-print, post-print
Citation Information
Benjamin T. Andrews, Shachi Gosavi, John M. Finke, José N. Onuchic, et al.. "The Dual-Basin Landscape in GFP Folding" Proceedings Of The National Academy Of Sciences Vol. 105 Iss. 34 (2008) p. 12283 - 12288
Available at: http://works.bepress.com/john_finke/4/