User:Jacob Holt/Sandbox 1: Difference between revisions
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=== Ligand Binding Pocket and Histidine Coordination === | === Ligand Binding Pocket and Histidine Coordination === | ||
The ligand binding pocket is a narrow tunnel that extends approximately 24 Å into the mostly hydrophobic interior of the protein. The ligand is stabilized by bending into a kinked conformation which creates a tight fit in the binding pocket tunnel, and by a hydrogen bond that occurs between the <scene name='87/877552/W258/1'>W 258</scene>side chain and the acyl carbonyl<ref name="Bai" />. The kink in the tunnel is formed by the conserved residues, <scene name='87/877552/Desaturation_site/8'>T 257 and W 149</scene> which are stabilized by the hydrogen bond shared with Q143<ref name="Bai" />. There are <scene name='87/877552/Substrate_orientation_w_fe/5'>two Fe2+ ions</scene> that interact with the substrate; the Fe2+ ions are coordinated by 9 histidine residues. One metal ion is coordinated by 4 histidines residues and a water molecule, and the other metal ion is coordinated by 5 histidine residues<ref name="Bai" />. <scene name='87/877552/Substrate_oreintation_fe_90deg/2'>When rotated 90 degrees</scene> the ligand is seen to be in a eclipsed position, indicating it is in its post-reaction form. The histidine residues position the metal ions 6.4 Å apart<ref name="Bai" />. | The ligand binding pocket is a narrow tunnel that extends approximately 24 Å into the mostly hydrophobic interior of the protein. The ligand is stabilized by bending into a kinked conformation which creates a tight fit in the binding pocket tunnel, and by a hydrogen bond that occurs between the <scene name='87/877552/W258/1'>W 258</scene> side chain and the acyl carbonyl<ref name="Bai" />. The kink in the tunnel is formed by the conserved residues, <scene name='87/877552/Desaturation_site/8'>T 257 and W 149</scene> which are stabilized by the hydrogen bond shared with Q143<ref name="Bai" />. There are <scene name='87/877552/Substrate_orientation_w_fe/5'>two Fe2+ ions</scene> that interact with the substrate; the Fe2+ ions are coordinated by 9 histidine residues. One metal ion is coordinated by 4 histidines residues and a water molecule, and the other metal ion is coordinated by 5 histidine residues<ref name="Bai" />. <scene name='87/877552/Substrate_oreintation_fe_90deg/2'>When rotated 90 degrees</scene> the ligand is seen to be in a eclipsed position, indicating it is in its post-reaction form. The histidine residues position the metal ions 6.4 Å apart<ref name="Bai" />. | ||
=== Desaturation Site === | === Desaturation Site === |