Sandbox 173: Difference between revisions
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There is the presence of a cationic amphipathic Helix 8, known as the fourth cytoplasmic loop, that spans from <scene name='Sandbox_173/Helix_8/1'>Asparagine 310 to Cysteine 323</scene> and is formed from the C-terminal tail anchoring to the membrane by | There is the presence of a cationic amphipathic Helix 8, known as the fourth cytoplasmic loop, that spans from <scene name='Sandbox_173/Helix_8/1'>Asparagine 310 to Cysteine 323</scene> and is formed from the C-terminal tail anchoring to the membrane by | ||
<scene name='Sandbox_173/Cys322_and_cys323/1'>Cysteine 322 and Cysteine 323</scene>, which are <scene name='Sandbox_173/Palmitates/ | <scene name='Sandbox_173/Cys322_and_cys323/1'>Cysteine 322 and Cysteine 323</scene>, which are <scene name='Sandbox_173/Palmitates/3'>palmitoylated</scene>. This helix runs approximately parallel to the cytoplasmic surface and is involved in Gtγ binding<ref>Article 9</ref>, as well as the modulation of rhodopsin-transducin interactions and rhodopsin-phospholipid interactions<ref>Article 12</ref>. | ||
A metal zinc ion bridge chelated by histidine side-chains and connected to the cytoplasmic ends of Helix 3 and 6 is observed to prevent receptor activation. This perhaps indicates that separation of these cytoplasmic ends would contribute to rhodopsin activation<ref>Article 10</ref>. | A metal zinc ion bridge chelated by histidine side-chains and connected to the cytoplasmic ends of Helix 3 and 6 is observed to prevent receptor activation. This perhaps indicates that separation of these cytoplasmic ends would contribute to rhodopsin activation<ref>Article 10</ref>. | ||
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As this ligand is bound in the 12-s-''trans'' conformation, there arises the non-bonding interactions between the C-13 methyl group and C-10 hydrogen that contribute to non-planarity. This leads to the ability of the chromophore polyene tail to undergo fast photoisomerization around the C-11=C-12 double bond during light-induced activation<ref>Article 2</ref>. Also, it is found that the C-11=C-12 double bond is pre-twisted in the ground state of rhodopsin, which is partly attributed to the C20 methyl group attached to C13 through interaction with Tryptophan 265. This pre-twist may give insight on the features of isomerization about this bond upon light activation <ref>Original article</ref>. | As this ligand is bound in the 12-s-''trans'' conformation, there arises the non-bonding interactions between the C-13 methyl group and C-10 hydrogen that contribute to non-planarity. This leads to the ability of the chromophore polyene tail to undergo fast photoisomerization around the C-11=C-12 double bond during light-induced activation<ref>Article 2</ref>. Also, it is found that the C-11=C-12 double bond is pre-twisted in the ground state of rhodopsin, which is partly attributed to the C20 methyl group attached to C13 through interaction with Tryptophan 265. This pre-twist may give insight on the features of isomerization about this bond upon light activation <ref>Original article</ref>. | ||
Somewhat enclosing this chromophore is a retinal binding pocket partially formed by the N-terminal domain overlaying the extracellular turns including Extracellular Helix 2, which folds into the molecular center<ref>Article 6</ref>. | Somewhat enclosing this chromophore is a retinal binding pocket partially formed by the N-terminal domain overlaying the extracellular turns including Extracellular Helix 2, which folds into the molecular center<ref>Article 6</ref>. | ||
==Function== | ==Function== | ||
