Sugar transporter of AtSWEET13 in inward-facing state with a substrate analog

Experimental Data Snapshot

  • Resolution: 2.79 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.247 
  • R-Value Observed: 0.251 

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This is version 1.2 of the entry. See complete history


Molecular mechanism of substrate recognition and transport by the AtSWEET13 sugar transporter

Han, L.Zhu, Y.P.Liu, M.Zhou, Y.Lu, G.Y.Lan, L.Wang, X.P.Zhao, Y.F.Zhang, X.C.

(2017) Proc Natl Acad Sci U S A 114: 10089-10094

  • DOI: https://doi.org/10.1073/pnas.1709241114
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Sugar Will Eventually be Exported Transporters (SWEETs) are recently identified sugar transporters that can discriminate and transport di- or monosaccharides across a membrane following the concentration gradient. SWEETs play key roles in plant biological processes, such as pollen nutrition, nectar secretion, seed filling, and phloem loading. SWEET13 from Arabidopsis thaliana (AtSWEET13) is an important sucrose transporter in pollen development. Here, we report the 2.8-Å resolution crystal structure of AtSWEET13 in the inward-facing conformation with a substrate analog, 2'-deoxycytidine 5'-monophosphate, bound in the central cavity. In addition, based on the results of an in-cell transport activity assay and single-molecule Förster resonance energy transfer analysis, we suggest a mechanism for substrate selectivity based on the size of the substrate-binding pocket. Furthermore, AtSWEET13 appears to form a higher order structure presumably related to its function.

  • Organizational Affiliation

    National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
sugar transporter293Arabidopsis thalianaMutation(s): 0 
Membrane Entity: Yes 
Find proteins for Q9FGQ2 (Arabidopsis thaliana)
Explore Q9FGQ2 
Go to UniProtKB:  Q9FGQ2
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9FGQ2
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on DCM

Download Ideal Coordinates CCD File 
C9 H14 N3 O7 P
Experimental Data & Validation

Experimental Data

  • Resolution: 2.79 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.247 
  • R-Value Observed: 0.251 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 75.78α = 90
b = 42.831β = 93.85
c = 116.553γ = 90
Software Package:
Software NamePurpose
HKL-2000data processing
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
the Ministry of Science and TechnologyChina2014CB910104 to XCZ
the Chinese Academy of SciencesChinaXDB080203 to XCZ
National Natural Science Foundation of ChinaChina31470745 to XCZ

Revision History  (Full details and data files)

  • Version 1.0: 2017-09-13
    Type: Initial release
  • Version 1.1: 2017-10-04
    Changes: Database references
  • Version 1.2: 2023-11-22
    Changes: Data collection, Database references, Refinement description