Abstract
Structural formation of segments plays pivotal roles in protein folding and stability, but how the segment influences the structural ensemble remains elusive. We engineered two hybrid proteins by replacing the central helical segment of immunoglobulin G binding domain of streptococcal protein G with an α‐helix or β~2~‐strand element of a structural homologue, the immunoglobulin G binding domain of streptococcal protein L. The results show that substitution by the α‐helical sequence retains a folded structure predominantly with a three‐stranded β‐sheet but slightly destabilizes the compact ensemble, while substitution by the β~2~‐strand sequence completely destroys the structural formation. The finding implies that the local segment may influence the tertiary structure and overall stability, and the tertiary interactions may modulate structural formation of the segment, which might be considered when studying protein folding, prediction, design, and engineering. © 2005 Wiley Periodicals, Inc. Biopolymers 79: 9–17, 2005
This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at [email protected]