RT Journal Article
SR Electronic
T1 How do brassinosteroids activate their receptors?
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 630640
DO 10.1101/630640
A1 Alexander S. Moffett
A1 Diwakar Shukla
YR 2019
UL http://biorxiv.org/content/early/2019/05/07/630640.abstract
AB Brassinosteroids (BRs) are an important class of plant growth hormones which signal through BRI1 and BAK1, leucine-rich repeat receptor-like kinases (LRR-RLKs). When bound to the BRI1 island domain, BRs act as a “molecular glue”, mediating interactions between BRI1 and BAK1 extracellular domains. However, it is unclear how much other factors contribute to BR-induced BRI1-BAK1 association, including stabilization of the BRI1 island domain and large conformational changes in BRI1. We use several molecular dynamics simulation-based methods to explore the contributions of each mechanism to BR-dependent Arabidopsis thaliana BRI1-BAK1 association. We find that specific BR interactions make major contributions to BRI1-BAK1 association free energy. BR binding stabilizes the BRI1 island domain, while BRI1 undergoes a large conformational change to form a secondary interface with BAK1. These results suggest that each mechanism plays a part in BR signal transduction while raising questions about the functional role of conformational dynamics in other LRR-RLKs.