Scaling properties of evolutionary paths in a biophysical model of protein adaptation. (28th May 2015)

• Record Type: Journal Article
• Authors: Manhart, Michael; Morozov, Alexandre V
• Is Part Of: Physical biology. Volume 12:Number 4(2015:Aug.)
• Publication Date: 2015-05-28
• Subjects: fitness landscapes -- evolutionary paths -- protein evolution -- scaling -- random walks; Biophysics -- Periodicals; Biochemistry -- Periodicals; Biology -- Data processing -- Periodicals; 570.5
• DOI: 10.1088/1478-3975/12/4/045001
• Languages: English
• ISSNs: 1478-3967

Abstract

Abstract: The enormous size and complexity of genotypic sequence space frequently requires consideration of coarse-grained sequences in empirical models. We develop scaling relations to quantify the effect of this coarse-graining on properties of fitness landscapes and evolutionary paths. We first consider evolution on a simple Mount Fuji fitness landscape, focusing on how the length and predictability of evolutionary paths scale with the coarse-grained sequence length and alphabet. We obtain simple scaling relations for both the weak- and strong-selection limits, with a non-trivial crossover regime at intermediate selection strengths. We apply these results to evolution on a biophysical fitness landscape that describes how proteins evolve new binding interactions while maintaining their folding stability. We combine the scaling relations with numerical calculations for coarse-grained protein sequences to obtain quantitative properties of the model for realistic binding interfaces and a full amino acid alphabet.