Optimization of the Gβ1 Domain by Computational Design and by in Vitro Evolution: Structural and Energetic Basis of Stabilization


Computational design and in vitro evolution are major strategies for stabilizing proteins. For the four critical positions 16, 18, 25, and 29 of the B domain of the streptococcal protein G (Gβ1), they identified the same optimal residues at positions 16 and 25, but not at 18 and 29. Here we analyzed the energetic contributions of the residues from these two approaches by single and double mutant analyses and determined crystal structures for a variant from the calculation (I16/L18/E25/K29) and from the selection (I16/I18/E25/F29). The structural analysis explains the observed differences in stabilization. Residues 16, 18, and 29 line an invagination, which results from a packing defect between the helix and the β-sheet of Gβ1. In all stabilized variants, residues with larger side-chains occur at these positions and packing is improved. In the selected variant, packing is better optimized than in the computed variant. Such differences in side-chain packing strongly affect stability but are difficult to evaluate by computation.

Submission Details


Submitter: Marie Ary

Submission Date: July 31, 2017, 11:46 a.m.

Version: 1

Publication Details
Wunderlich M;Max KE;Roske Y;Mueller U;Heinemann U;Schmid FX,J Mol Biol (2007) Optimization of the Gβ1 domain by computational design and by in vitro evolution: structural and energetic basis of stabilization. PMID:17868696
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)