Myoglobin: Difference between revisions
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The globin consists mostly of [[Helices in Proteins|alpha helices]] shown in <scene name='23/238129/2ndary_structure/2'>pink</scene>; it has no beta sheets and its nonhelical segments mostly serve as links that connect the helices. Look down the barrel of some of the longer helices. Are they all straight? The eight structurally conserved alpha helices are labelled <scene name='23/238129/Helix_labels/2'>A through H</scene>. The protein is colored as a N-->C rainbow in this view; the N terminus is blue, while the C terminus is red. | The globin consists mostly of [[Helices in Proteins|alpha helices]] shown in <scene name='23/238129/2ndary_structure/2'>pink</scene>; it has no beta sheets and its nonhelical segments mostly serve as links that connect the helices. Look down the barrel of some of the longer helices. Are they all straight? The eight structurally conserved alpha helices are labelled <scene name='23/238129/Helix_labels/2'>A through H</scene>. The protein is colored as a N-->C rainbow in this view; the N terminus is blue, while the C terminus is red. | ||
The <scene name='23/238129/Heme/3'>heme ligand</scene>, and specifically the iron atom in the middle of the heme, is what binds oxygen in myoglobin. In this representation, the heme alone is shown in ball and stick form with its C, N and O atoms displayed as grey, blue, and red balls respectively. The iron atom is shown in orange, and is in spacefill to better illustrate its interactions with the heme. The iron is bound by four nitrogen atoms found in the heme ring, as well as an <scene name='23/238129/Fe_ligands/1'>amino acid</scene> from the protein chain. Which amino acid from the myoglobin protein binds to the iron? Notice that in the oxygenated state, the iron is in the plane of the heme ring. | The <scene name='23/238129/Heme/3'>heme ligand</scene>, and specifically the iron atom in the middle of the heme, is what binds oxygen in myoglobin. In this representation, the heme alone is shown in ball and stick form with its C, N and O atoms displayed as grey, blue, and red balls respectively. The iron atom is shown in orange, and is in spacefill to better illustrate its interactions with the heme. The iron is bound by four nitrogen atoms found in the heme ring, as well as an <scene name='23/238129/Fe_ligands/1'>amino acid</scene> from the protein chain. Which amino acid from the myoglobin protein binds to the iron? Notice that in the oxygenated state, the iron is in the plane of the heme ring. In the <scene name='23/238129/Deoxy_heme_fe_plane/1'>deoxy</scene> (no oxygen) state, the Fe atom is slightly above the plane of the heme, and a second <scene name='23/238129/Deoxy_heme_his/1'>amino acid</scene> coordinates with the iron in the heme ring. | ||