Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Published Online May 28, 2009
Science DOI: 10.1126/science.1173654

Reports

Submitted on March 17, 2009
Accepted on April 30, 2009

Structure and Mechanism of an Amino Acid Antiporter

Xiang Gao 1{dagger}, Feiran Lu 1{dagger}, Lijun Zhou 1{dagger}, Shangyu Dang 1, Linfeng Sun 1, Xiaochun Li 1, Jiawei Wang 1, Yigong Shi 2*

1 State Key Laboratory of Bio-membrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China.; Center for Structural Biology, Department of Biological Sciences & Biotechnology, Tsinghua University, Beijing 100084, China.
2 Center for Structural Biology, Department of Biological Sciences & Biotechnology, Tsinghua University, Beijing 100084, China.; School of Medicine, Tsinghua University, Beijing 100084, China.

* To whom correspondence should be addressed.
Yigong Shi , E-mail: shi-lab{at}tsinghua.edu.cn

{dagger}These author contributed equally to this work.

Virulent enteric pathogens such as Escherichia coli strain O157:H7 rely on acid resistance (AR) systems to survive acidic environment in the stomach. A major component of AR is an arginine-dependent arginine:agmatine antiporter that expels intracellular protons. Here, we report the crystal structure of AdiC, the arginine:agmatine antiporter from E. coli O157:H7 and a member of the amino acid/polyamine/organocation (APC) superfamily of transporters at 3.6 Å resolution. The overall fold is similar to that of several Na+-coupled symporters. AdiC contains 12 transmembrane segments, forms a homodimer, and exists in an outward-facing, open conformation in the crystals. A conserved, acidic pocket opens to the periplasm. Structural and biochemical analysis reveals the essential ligand-binding residues, defines the transport route, and suggests a conserved mechanism for the antiporter activity.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
The Rocking Bundle: A Mechanism for Ion-Coupled Solute Flux by Symmetrical Transporters.
L. R. Forrest and G. Rudnick (2009)
Physiology 24, 377-386
   Abstract »    Full Text »    PDF »
Highlights From the Literature.
(2009)
Physiology 24, 276-280
   Full Text »    PDF »
Mutation of Asparagine 76 in the Center of Glutamine Transporter SNAT3 Modulates Substrate-induced Conductances and Na+ Binding.
S. Broer, H.-P. Schneider, A. Broer, and J. W. Deitmer (2009)
J. Biol. Chem. 284, 25823-25831
   Abstract »    Full Text »    PDF »
A Conserved Na+ Binding Site of the Sodium-coupled Neutral Amino Acid Transporter 2 (SNAT2).
Z. Zhang, T. Albers, H. L. Fiumera, A. Gameiro, and C. Grewer (2009)
J. Biol. Chem. 284, 25314-25323
   Abstract »    Full Text »    PDF »
Structure and Mechanism of a Na+-Independent Amino Acid Transporter.
P. L. Shaffer, A. Goehring, A. Shankaranarayanan, and E. Gouaux (2009)
Science 325, 1010-1014
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)