9LUO

Cryo-EM structure of Arabidopsis thaliana RGA in complex with GID1A, SLY1, and ASK2 (focused map)

Summary for 9LUO

• Entry DOI: 10.2210/pdb9luo/pdb
• EMDB information: 63400
• Descriptor: DELLA protein RGA, F-box protein GID2, SKP1-like protein 1B (3 entities in total)
• Functional Keywords: gibberellin, della motif, gras domain, plant growth, hormone
• Biological source: Arabidopsis thaliana (thale cress); More
• Total number of polymer chains: 3
• Total formula weight: 100990.81

Authors

Islam, S.,Park, K.,Kwon, E.,Kim, D.Y. (deposition date: 2025-02-09, release date: 2025-07-09, Last modification date: 2025-07-23)

Primary citation

Islam, S.,Park, K.,Xia, J.,Kwon, E.,Kim, D.Y.
Structural insights into gibberellin-mediated DELLA protein degradation.
Mol Plant, 18:1210-1221, 2025

PubMed Abstract: Gibberellin promotes plant growth by downregulating DELLA proteins, which act as growth repressors. In the presence of gibberellin, the gibberellin receptor GID1 binds DELLA proteins, triggering their degradation through polyubiquitination by the SCF ubiquitin E3 ligase. Despite extensive studies, the molecular mechanisms by which DELLA proteins assemble with SCF to regulate plant growth remain poorly understood. Here, we present two cryo-electron microscopy structures of the Arabidopsis thaliana DELLA protein RGA in complex with GID1A and GID1A-SLY1-ASK2, respectively. Structural analyses revealed that RGA interacts with GID1A and SLY1 through nonoverlapping binding surfaces, stabilizing the proteins. This suggests that the SCF-RGA-GID1A complex assembles through a stepwise stabilization process induced by gibberellin. Furthermore, structural comparison with GRAS proteins indicates that RGA does not interact with IDD-family transcription factors when bound to SLY1, suggesting that DELLA protein binding to GID1/SLY1 and to transcription factors is mutually exclusive. These findings provide new insights into the gibberellin-mediated regulation of transcription factor activity by DELLA proteins.

PubMed: 40542507
DOI: 10.1016/j.molp.2025.06.010

Experimental method

ELECTRON MICROSCOPY (3.07 Å)