Structural highlights
Function
[ADIC_ECO57] Major component of the acid-resistance (AR) system allowing enteric pathogens to survive the acidic environment in the stomach. Exchanges extracellular arginine for its intracellular decarboxylation product agmatine (Agm) thereby expelling intracellular protons.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
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.
Structure and mechanism of an amino acid antiporter.,Gao X, Lu F, Zhou L, Dang S, Sun L, Li X, Wang J, Shi Y Science. 2009 Jun 19;324(5934):1565-8. Epub 2009 May 28. PMID:19478139[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Gao X, Lu F, Zhou L, Dang S, Sun L, Li X, Wang J, Shi Y. Structure and mechanism of an amino acid antiporter. Science. 2009 Jun 19;324(5934):1565-8. Epub 2009 May 28. PMID:19478139