4AOE

Biomphalaria glabrata Acetylcholine-binding protein type 2 (BgAChBP2)

Summary for 4AOE

• Entry DOI: 10.2210/pdb4aoe/pdb
• Related: 4AOD
• EMDB information: 2055
• Descriptor: ACETYLCHOLINE-BINDING PROTEIN TYPE 2 (1 entity in total)
• Functional Keywords: acetylcholine-binding protein, ligand gated ion channel, lgic, cys-loop receptor, achbp, acetylcholine, achr, acetylcholine receptor, myasthenia gravis, pentagonal dodecahedron, nicotinic, schistosoma mansoni, bilharziosis
• Biological source: BIOMPHALARIA GLABRATA
• Total number of polymer chains: 5
• Total formula weight: 117668.57

Authors

Saur, M.,Moeller, V.,Kapetanopoulos, K.,Braukmann, S.,Gebauer, W.,Tenzer, S.,Markl, J. (deposition date: 2012-03-26, release date: 2012-08-29, Last modification date: 2024-10-16)

Primary citation

Saur, M.,Moeller, V.,Kapetanopoulos, K.,Braukmann, S.,Gebauer, W.,Tenzer, S.,Markl, J.
Acetylcholine-Binding Protein in the Hemolymph of the Planorbid Snail Biomphalaria Glabrata is a Pentagonal Dodecahedron (60 Subunits)
Plos One, 7:43685-, 2012

PubMed Abstract: Nicotinic acetylcholine receptors (nAChR) play important neurophysiological roles and are of considerable medical relevance. They have been studied extensively, greatly facilitated by the gastropod acetylcholine-binding proteins (AChBP) which represent soluble structural and functional homologues of the ligand-binding domain of nAChR. All these proteins are ring-like pentamers. Here we report that AChBP exists in the hemolymph of the planorbid snail Biomphalaria glabrata (vector of the schistosomiasis parasite) as a regular pentagonal dodecahedron, 22 nm in diameter (12 pentamers, 60 active sites). We sequenced and recombinantly expressed two ∼25 kDa polypeptides (BgAChBP1 and BgAChBP2) with a specific active site, N-glycan site and disulfide bridge variation. We also provide the exon/intron structures. Recombinant BgAChBP1 formed pentamers and dodecahedra, recombinant BgAChBP2 formed pentamers and probably disulfide-bridged di-pentamers, but not dodecahedra. Three-dimensional electron cryo-microscopy (3D-EM) yielded a 3D reconstruction of the dodecahedron with a resolution of 6 Å. Homology models of the pentamers docked to the 6 Å structure revealed opportunities for chemical bonding at the inter-pentamer interfaces. Definition of the ligand-binding pocket and the gating C-loop in the 6 Å structure suggests that 3D-EM might lead to the identification of functional states in the BgAChBP dodecahedron.

PubMed: 22916297
DOI: 10.1371/JOURNAL.PONE.0043685

Experimental method

ELECTRON MICROSCOPY (6 Å)