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Structure and Mechanism of an Amino Acid Antiporter.
- Source :
-
Science . 6/19/2009, Vol. 324 Issue 5934, p1565-1568. 4p. - Publication Year :
- 2009
-
Abstract
- 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 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. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00368075
- Volume :
- 324
- Issue :
- 5934
- Database :
- Academic Search Index
- Journal :
- Science
- Publication Type :
- Academic Journal
- Accession number :
- 43026197
- Full Text :
- https://doi.org/10.1126/science.1173654