5XPD image
Entry Detail
PDB ID:
5XPD
Title:
Sugar transporter of AtSWEET13 in inward-facing state with a substrate analog
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2017-06-01
Release Date:
2017-09-13
Method Details:
Experimental Method:
Resolution:
2.79 Å
R-Value Free:
0.28
R-Value Work:
0.24
R-Value Observed:
0.25
Space Group:
C 1 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:sugar transporter
Chain IDs:A
Chain Length:293
Number of Molecules:1
Biological Source:Arabidopsis thaliana
Ligand Molecules
Primary Citation
Molecular mechanism of substrate recognition and transport by the AtSWEET13 sugar transporter
Proc. Natl. Acad. Sci. U.S.A. 114 10089 10094 (2017)
PMID: 28878024 DOI: 10.1073/pnas.1709241114

Abstact

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.

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