Binding site of AChR: Difference between revisions
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[[Image:M2 helices.PNG|thumb|350px|Fig. 2. Top view of GLIC M2 helices|left]] | [[Image:M2 helices.PNG|thumb|350px|Fig. 2. Top view of GLIC M2 helices|left]] | ||
[[Image:Mechanism of GLIC.PNG|350px|Fig. | [[Image:Mechanism of GLIC.PNG|350px|Fig. 3. Open GLIC and closed ELIC structure comarison green is GLIC and red is ELIC|right]] | ||
X-ray structure of homologues of the extracellular domain(ECD) of nAChRs have also been described:the acetylcholine binding protein(AChBP) co-crystallized with agonists and antagonists, and the ECD of α1-nAChRs. Most pLGICs undergo desensitization on prolonged exposure to agonist, complicating structural investigations of the transient open conformation. <ref>PMID:18987633</ref> The overall architecture of bacterial Gloeobacter violaceus pentameric ligand-gated ion(GLIC) is similar to nAChR(Fig 1). The five subunits are arranged in a barrel-like manner around a central symmetry axis that coincides with the ion permeation pathway.<ref>PMID:18987633</ref> The transmembrane domain of each subunit consists of four helices and M2 helices form the wall of the pore(Fig 2).Figure 2 shows that helix backbones and side chains facing the pore are depicted. Hydrophobic, polar and negative residues are coloured yellow, green and red respectively. The M2 axes are tilted with respect to the pore axis, with outer hydrophobic side chain oriented toward the helix interfaces, and inner polar side chains oriented towards the pore.<ref>PMID:18987633</ref> | X-ray structure of homologues of the extracellular domain(ECD) of nAChRs have also been described:the acetylcholine binding protein(AChBP) co-crystallized with agonists and antagonists, and the ECD of α1-nAChRs. Most pLGICs undergo desensitization on prolonged exposure to agonist, complicating structural investigations of the transient open conformation. <ref>PMID:18987633</ref> The overall architecture of bacterial Gloeobacter violaceus pentameric ligand-gated ion(GLIC) is similar to nAChR(Fig 1). The five subunits are arranged in a barrel-like manner around a central symmetry axis that coincides with the ion permeation pathway.<ref>PMID:18987633</ref> The transmembrane domain of each subunit consists of four helices and M2 helices form the wall of the pore(Fig 2).Figure 2 shows that helix backbones and side chains facing the pore are depicted. Hydrophobic, polar and negative residues are coloured yellow, green and red respectively. The M2 axes are tilted with respect to the pore axis, with outer hydrophobic side chain oriented toward the helix interfaces, and inner polar side chains oriented towards the pore.<ref>PMID:18987633</ref> | ||