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5xpd

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

Structural highlights

5xpd is a 1 chain structure with sequence from Arabidopsis thaliana. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.788Å
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

SWT13_ARATH Mediates both low-affinity uptake and efflux of sugar across the plasma membrane. Involved in nurturing the male gametophyte (PubMed:25988582).^[1] ^[2]

Publication Abstract from PubMed

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-A 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 Forster 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.

Molecular mechanism of substrate recognition and transport by the AtSWEET13 sugar transporter.,Han L, Zhu Y, Liu M, Zhou Y, Lu G, Lan L, Wang X, Zhao Y, Zhang XC Proc Natl Acad Sci U S A. 2017 Sep 19;114(38):10089-10094. doi:, 10.1073/pnas.1709241114. Epub 2017 Sep 6. PMID:28878024^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Chen LQ, Qu XQ, Hou BH, Sosso D, Osorio S, Fernie AR, Frommer WB. Sucrose efflux mediated by SWEET proteins as a key step for phloem transport. Science. 2012 Jan 13;335(6065):207-11. PMID:22157085 doi:10.1126/science.1213351
↑ Eom JS, Chen LQ, Sosso D, Julius BT, Lin IW, Qu XQ, Braun DM, Frommer WB. SWEETs, transporters for intracellular and intercellular sugar translocation. Curr Opin Plant Biol. 2015 Jun;25:53-62. PMID:25988582 doi:10.1016/j.pbi.2015.04.005
↑ Han L, Zhu Y, Liu M, Zhou Y, Lu G, Lan L, Wang X, Zhao Y, Zhang XC. Molecular mechanism of substrate recognition and transport by the AtSWEET13 sugar transporter. Proc Natl Acad Sci U S A. 2017 Sep 19;114(38):10089-10094. doi:, 10.1073/pnas.1709241114. Epub 2017 Sep 6. PMID:28878024 doi:http://dx.doi.org/10.1073/pnas.1709241114