Publication Date:
2009-05-30
Description:
Virulent enteric pathogens such as Escherichia coli strain O157:H7 rely on acid-resistance (AR) systems to survive the 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 A 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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gao, Xiang -- Lu, Feiran -- Zhou, Lijun -- Dang, Shangyu -- Sun, Linfeng -- Li, Xiaochun -- Wang, Jiawei -- Shi, Yigong -- New York, N.Y. -- Science. 2009 Jun 19;324(5934):1565-8. doi: 10.1126/science.1173654. Epub 2009 May 28.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉State Key Laboratory of Bio-membrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19478139" target="_blank"〉PubMed〈/a〉
Keywords:
Agmatine/metabolism
;
Amino Acid Sequence
;
Amino Acid Transport Systems/*chemistry/genetics/metabolism/physiology
;
Antiporters/*chemistry/genetics/metabolism/physiology
;
Arginine/metabolism
;
Conserved Sequence
;
Crystallography, X-Ray
;
Escherichia coli O157/*chemistry/genetics/metabolism
;
Escherichia coli Proteins/*chemistry/genetics/metabolism/physiology
;
Models, Molecular
;
Molecular Sequence Data
;
Protein Conformation
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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