一個蛋白的晶體結構而已。所有的結構都是世界首次，否則不能發表。

這個蛋白的功能是已知的。但是結構不清楚。清華解出了蛋白的晶體結構（分辨率有點低）， 對了解結構與功能的關係有幫助。

以下為論文摘要。


Crystal structure of the human glucose transporter GLUT1

Dong Deng, Chao Xu, Pengcheng Sun, Jianping Wu, Chuangye Yan, Mingxu Hu & Nieng Yan
AffiliationsContributionsCorresponding author
Nature 510, 121–125 (05 June 2014) doi:10.1038/nature13306
Received 26 January 2014 Accepted 01 April 2014 Published online 18 May 2014
PDF
Citation
Reprints
Rights & permissions
Article metrics
Abstract
Abstract• Introduction• Structure determination of GLUT1• Implications for ligand binding• Mapping of disease-related mutations• Critical role of the ICH domain• The extracellular gate• Discussion• Methods summary• Accession codes• References• Acknowledgements• Author information• Extended data figures and tables
The glucose transporter GLUT1 catalyses facilitative diffusion of glucose into erythrocytes and is responsible for glucose supply to the brain and other organs. Dysfunctional mutations may lead to GLUT1 deficiency syndrome, whereas overexpression of GLUT1 is a prognostic indicator for cancer. Despite decades of investigation, the structure of GLUT1 remains unknown. Here we report the crystal structure of human GLUT1 at 3.2 Å resolution. The full-length protein, which has a canonical major facilitator superfamily fold, is captured in an inward-open conformation. This structure allows accurate mapping and potential mechanistic interpretation of disease-associated mutations in GLUT1. Structure-based analysis of these mutations provides an insight into the alternating access mechanism of GLUT1 and other members of the sugar porter subfamily. Structural comparison of the uniporter GLUT1 with its bacterial homologue XylE, a proton-coupled xylose symporter, allows examination of the transport mechanisms of both passive facilitators and active transporters.