1I9B: X-RAY STRUCTURE OF ACETYLCHOLINE BINDING PROTEIN (ACHBP)

Citation:
Abstract
Pentameric ligand gated ion-channels, or Cys-loop receptors, mediate rapid chemical transmission of signals. This superfamily of allosteric transmembrane proteins includes the nicotinic acetylcholine (nAChR), serotonin 5-HT3, gamma-aminobutyric-acid (GABAA and GABAC) and glycine receptors. Biochemical and electrophysiological information on the prototypic nAChRs is abundant but structural data at atomic resolution have been missing. Here we present the crystal structure of molluscan acetylcholine-binding protein (AChBP), a structural and functional homologue of the amino-terminal ligand-binding domain of an nAChR alpha-subunit. In the AChBP homopentamer, the protomers have an immunoglobulin-like topology. Ligand-binding sites are located at each of five subunit interfaces and contain residues contributed by biochemically determined 'loops' A to F. The subunit interfaces are highly variable within the ion-channel family, whereas the conserved residues stabilize the protomer fold. This AChBP structure is relevant for the development of drugs against, for example, Alzheimer's disease and nicotine addiction.
PDB ID: 1I9BDownload
MMDB ID: 16027
PDB Deposition Date: 2001/3/18
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 2.7  Å
Source Organism:
Similar Structures:
Biological Unit for 1I9B: pentameric; determined by author and by software (PISA)
Molecular Components in 1I9B
Label Count Molecule
Proteins (5 molecules)
5
Acetylcholine Binding Protein
Molecule annotation
Chemicals (13 molecules)
1
8
2
5
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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