3NCY

X-ray crystal structure of an arginine agmatine antiporter (AdiC) in complex with a Fab fragment

Replaces:  3HQK

Summary for 3NCY

• Entry DOI: 10.2210/pdb3ncy/pdb
• Descriptor: AdiC, Fab Heavy chain, Fab Light chain (3 entities in total)
• Functional Keywords: membrane protein complex with fab fragment, arginine agmatine antiporter, virtual proton pump, apc superfamily, immune system, transport protein
• Biological source: Salmonella enterica subsp. enterica serovar Typhimurium; More
• Total number of polymer chains: 8
• Total formula weight: 281021.18

Authors

Fang, Y.,Jayaram, H.,Shane, T.,Komalkova-Partensky, L.,Wu, F.,Williams, C.,Xiong, Y.,Miller, C. (deposition date: 2010-06-06, release date: 2010-08-18, Last modification date: 2024-11-06)

Primary citation

Fang, Y.,Jayaram, H.,Shane, T.,Komalkova-Partensky, L.,Wu, F.,Williams, C.,Xiong, Y.,Miller, C.
Structure of a prokaryotic virtual proton pump at 3.2 A resolution.
Nature, 460:1040-1043, 2009

PubMed Abstract: To reach the mammalian gut, enteric bacteria must pass through the stomach. Many such organisms survive exposure to the harsh gastric environment (pH 1.5-4) by mounting extreme acid-resistance responses, one of which, the arginine-dependent system of Escherichia coli, has been studied at levels of cellular physiology, molecular genetics and protein biochemistry. This multiprotein system keeps the cytoplasm above pH 5 during acid challenge by continually pumping protons out of the cell using the free energy of arginine decarboxylation. At the heart of the process is a 'virtual proton pump' in the inner membrane, called AdiC, that imports L-arginine from the gastric juice and exports its decarboxylation product agmatine. AdiC belongs to the APC superfamily of membrane proteins, which transports amino acids, polyamines and organic cations in a multitude of biological roles, including delivery of arginine for nitric oxide synthesis, facilitation of insulin release from pancreatic beta-cells, and, when inappropriately overexpressed, provisioning of certain fast-growing neoplastic cells with amino acids. High-resolution structures and detailed transport mechanisms of APC transporters are currently unknown. Here we describe a crystal structure of AdiC at 3.2 A resolution. The protein is captured in an outward-open, substrate-free conformation with transmembrane architecture remarkably similar to that seen in four other families of apparently unrelated transport proteins.

PubMed: 19578361
DOI: 10.1038/nature08201

Experimental method

X-RAY DIFFRACTION (3.2 Å)