Sandbox Reserved 1174: Difference between revisions

The LPA₁ receptor consists of seven transmembrane alpha helices. It lies in the membrane as shown in Figure 2, and as shown by the <scene name='72/721545/Membrane/4'>fatty acid</scene> bound in the crystallization of LPA₁ in orange. Most <scene name='72/721545/Polarity/3'>polar</scene> (red) reside on the intracellular and extracellular areas of the receptor, while most residues positioned on the trans membrane helices inside the membrane are hydrophobic (blue). A cytochrome b (b₅₆₂RIL) protein was inserted into the third intracellular loop to facilitate crystallization (Figure 2). 

Three native <scene name='72/721545/Disulfides/2'>disulfide bonds</scene> in the extracellular region of this receptor provide fold stability.<ref name= "Chrencik"/> The first disulfide bond constrains the N terminal helix to extracellular loop(ECL) 2. The second disulfide bond shapes ECL2, and the third binds ECL3 to one of the transmembrane alpha helices. The <scene name='72/721545/N-terminus/2'>N-terminus</scene> functions like a cap on the extracellular side of the protein, packing tightly against ECL1 and ECL2. The N-terminus alpha helix also provides <scene name='72/721545/34_39_40/3'>polar amino acids</scene> that interact with the ligand when bound.