9LVA | pdb_00009lva

IAA-bound AUX1

• PDB DOI: https://doi.org/10.2210/pdb9LVA/pdb
• EM Map EMD-63417: EMDB EMDataResource

• Classification: PROTEIN TRANSPORT
• Organism(s): Arabidopsis thaliana
• Expression System: Homo sapiens
• Mutation(s): No 
• Membrane Protein: Yes  MemProtMD


• Deposited: 2025-02-12 Released: 2025-07-23 
• Deposition Author(s): Wang, C.C., Jing, D., Kong, F., Huang, G.X.Y., Shi, Y.G.
• Funding Organization(s): Other government

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.52 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Structural basis of auxin binding and transport by Arabidopsis thaliana AUX1.

Jing, D., Kong, F., Lu, X., Huang, G., Huang, J., Wang, H., Shi, Y., Wang, C.

(2025) Proc Natl Acad Sci U S A 122: e2513424122-e2513424122

• PubMed: 40720658 
• DOI: https://doi.org/10.1073/pnas.2513424122
• Primary Citation of Related Structures:  
  9LVA, 9LVB


• PubMed Abstract: 
  

  Indole-3-acetic acid (IAA), the major form of auxin, is essential for plant growth. Auxin resistant 1 (AUX1), the first identified auxin importer, plays a crucial role in polar auxin transport (PAT). Here, we present cryo-EM structures of Arabidopsis thaliana AUX1 in the IAA-free and IAA-bound states. AUX1 exists as a monomer that contains 11 transmembrane helices (TMs). TMs 1 to 5 and 6 to 10 constitute the two halves of a classic LeuT-fold, and TM11 interacts with both halves at the interface. In the IAA-bound state, IAA is specifically recognized in a central pocket formed by TM1, TM3, TM6, and TM8. In the presence of IAA, TM1 and TM6 undergo marked conformational changes that are critical for IAA transport. His249 stands out to be a key residue for substrate uptake and release. Our structures reveal the molecular basis for AUX1-mediated IAA binding and transport.

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Organizational Affiliation: 
• College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang Province 310024, China.
Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang Province 310024, China.
Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 57.31 kDa 
• Atom Count: 3,323 
• Modeled Residue Count: 415 
• Deposited Residue Count: 510 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Auxin transporter protein 1	A	510	Arabidopsis thaliana	Mutation(s): 0  Gene Names: AUX1 Membrane Entity: Yes
UniProt
Find proteins for Q96247 (Arabidopsis thaliana) Explore Q96247  Go to UniProtKB:  Q96247

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
IAC (Subject of Investigation/LOI)	B [auth A]	1H-INDOL-3-YLACETIC ACID C10 H9 N O2 SEOVTRFCIGRIMH-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.52 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX	1.21.1_5286

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2025-07-23 
Deposition Author(s): Wang, C.C., Jing, D., Kong, F., Huang, G.X.Y., Shi, Y.G.

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Funding Organization	Location	Grant Number
Other government		2020C04001

Revision History  

• Version 1.0: 2025-07-23
  Type: Initial release
  
• Version 1.1: 2025-09-10
  Changes: Data collection, Database references