9JUM image
Deposition Date 2024-10-08
Release Date 2025-03-05
Last Version Date 2025-05-14
Entry Detail
PDB ID:
9JUM
Title:
Structure of Arabidopsis thaliana ABCB1 with brassinolide and AMP-PNP bound in the inward-facing conformation
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
3.10 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:ABC transporter B family member 1
Gene (Uniprot):ABCB1
Chain IDs:A
Chain Length:1327
Number of Molecules:1
Biological Source:Arabidopsis thaliana
Primary Citation
Structures and mechanisms of the ABC transporter ABCB1 from Arabidopsis thaliana.
Structure 33 903 915.e5 (2025)
PMID: 40101709 DOI: 10.1016/j.str.2025.02.008

Abstact

The Arabidopsis thaliana auxin transporter ABCB1 plays a fundamental role in the regulation of plant growth and development. While its homolog ABCB19 was previously shown to transport brassinosteroids (BR), another class of essential hormones, the ability of ABCB1 to mediate BR transport has remained unexplored. In this study we show that ABCB1 also transports brassinosteroids with an in vitro brassinolide (BL) transport assay. Using single-particle cryo-electron microscopy, we determined ABCB1 structures in multiple inward-facing conformations in the apo state, ANP-bound state, BL-bound state, and the both BL- and ANP-bound state. BL binds to the large cavity of two transmembrane domains, inducing a slight conformational change. Additionally, we obtained the structure of ABCB1 in an outward-facing conformation. By comparing these different conformations, we elucidated the possible mechanism of hormone transport by ABCB1. These high-resolution structures help us to understand the structural basis for hormone recognition and transport mechanisms of ABCB1.

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