TALEs from a spring -- superelasticity of Tal effector protein structures

TL;DR

This study uses a force-probe setup to investigate the superelastic properties of TALE proteins, revealing their spring-like behavior, nonlinear stiffness at large deformations, and key flexible regions influencing conformational changes.

Contribution

It demonstrates the superelastic behavior of TALE proteins and identifies soft spots critical for conformational transmission, linking structure and dynamics.

Findings

TALE proteins behave like linear springs under moderate deformation.

They exhibit nonlinear stiffness and increased rigidity at larger stretches.

Soft spots in the structure are key to conformational motion transmission.

Abstract

A simple force-probe setup is employed to study the mechanical properties of transcription activator-like effector (TALE) proteins in computer experiments. It is shown that their spring-like arrangement benefits superelastic behaviour which is manifested by large-scale global conformational changes along the helical axis, thus linking structure and dynamics in TALE proteins. As evidenced from the measured force-extension curves the dHax3 and PthXo1 TALEs behave like linear springs, obeying Hooke's law, for moderate global structural changes. For larger deformations, however, the proteins exhibit nonlinearities and the structures become stiffer the more they are stretched. Flexibility is not homogeneously distributed over TALE structure, but instead soft spots which correspond to the RVD loop residues and present key agents in the transmission of conformational motions are identified.