Elucidating Binding Mechanism of Plant Hormones Involved in Growth and Development

Diwakar Shukla, University of Illinois at Urbana-Champaign

Usage Details

Plant hormones are small molecules produced by the plant that play a vital role in its growth and development. Brassinolide is a plant hormone that is responsible for several critical processes in plants, including elongation and cell division. It binds to the extracellular domain of the receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1), starting a signaling cascade of reactions. Although the steps of the binding process are known, only limited knowledge exists about the specific mechanisms and the role of critical amino acids. This project aims to address several unanswered questions about the binding process. In particular, it would helpful to obtain mechanistic insights into why brassinolide has a stronger affinity for BRI1 while molecules, like castasterone, which is a precursor to brassinolide and exists in higher concentration, does not bind well. This study also aims to investigate the role of different amino acids in the protein involved in the binding process and potentially engineer the BRI1 receptor to strongly bind castasterone, leading to a higher growth rate. The student will conduct the simulations for several systems using conventional Molecular Dynamics as well as using Alchemical Free-Energy Perturbation methods, with an aim of understanding the biophysical mechanisms involved in the hormone binding process and designing mutations to improve the binding affinity of castasterone.