703DSS: Difference between revisions
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== Structure == | == Structure == | ||
The 5-HT3 receptor is bullet-shaped and consists of five subunits (A-E) that form an oligomer. In the center of this pentamer of subunits is a ligand-gated ion channel full of water, which the five subunits enclose pseudo-symmetrically. Each subunit of the 5-HT3 receptor consists of three regions; the extracellular region, the transmembrane region, and the intracellular region.<ref>Barnes, N., Hales, T., Lummis, S., & Peters, J. (2009). The 5-HT3 receptor – the relationship between structure and function. Neuropharmacology, 273-284</ref> | The 5-HT3 receptor is bullet-shaped and consists of five subunits (A-E) that form an oligomer. In the center of this pentamer of subunits is a ligand-gated ion channel full of water, which the five subunits enclose pseudo-symmetrically. Each subunit of the 5-HT3 receptor consists of three regions; the extracellular region, the transmembrane region, and the intracellular region.<ref name="barnes">Barnes, N., Hales, T., Lummis, S., & Peters, J. (2009). The 5-HT3 receptor – the relationship between structure and function. Neuropharmacology, 273-284</ref> | ||
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These <scene name='71/716487/Binding_site/1'>binding sites</scene> are located between two bordering subunits, assembled from three alpha-helices of one subunit and three beta-strands from the other subunit. Such connection creates a binding pocket with a small, select number of residues from each subunit pointed into the binding pocket, as opposed to the large remainder of residues that are pointing away from the binding pocket. <ref name="hassaine">Hassaine, G., Deluz, C., Grasso, L., Wyss, R., Tol, M., Hovius, R., . . . Nury, H. (2014). X-ray structure of the mouse serotonin 5-HT3 receptor. Nature, 276-281.</ref> This binding pocket shrinks around agonists, encapsulating them, and widens around antagonists, repulsing them. | These <scene name='71/716487/Binding_site/1'>binding sites</scene> are located between two bordering subunits, assembled from three alpha-helices of one subunit and three beta-strands from the other subunit. Such connection creates a binding pocket with a small, select number of residues from each subunit pointed into the binding pocket, as opposed to the large remainder of residues that are pointing away from the binding pocket. <ref name="hassaine">Hassaine, G., Deluz, C., Grasso, L., Wyss, R., Tol, M., Hovius, R., . . . Nury, H. (2014). X-ray structure of the mouse serotonin 5-HT3 receptor. Nature, 276-281.</ref> This binding pocket shrinks around agonists, encapsulating them, and widens around antagonists, repulsing them. | ||
The transmembrane region is within the C-terminus region, and contains four alpha-helical domains within it (M1-M4) that stretch the length of this inner, transmembrane area. These four alpha-helical domains conduct the channel openings via ion selectivity, depending on both charge and size.<ref name="hassaine" /> M2, the porous domain, contains rings of charged amino acids at both its start and its end, accounting for M2’s main contribution to ion selectivity. The M3 and M4 alpha-helices create a large loop with one another, thus assembling the intracellular region | The transmembrane region is within the C-terminus region, and contains four alpha-helical domains within it (M1-M4) that stretch the length of this inner, transmembrane area. These four alpha-helical domains conduct the channel openings via ion selectivity, depending on both charge and size.<ref name="hassaine" /> M2, the porous domain, contains rings of charged amino acids at both its start and its end, accounting for M2’s main contribution to ion selectivity. The M3 and M4 alpha-helices create a large loop with one another, thus assembling the intracellular region. <ref name="barnes"> | ||
== Function == | == Function == | ||
