Sandbox Reserved 830: Difference between revisions
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Helices A and C have breaks in the hydrogen-bonding pattern of their structure, forming tight substitute hydrogen bonds with water molecules. Indeed, it results in a kink in helix A (<scene name='56/568028/Kink_helixa/1'>and slightly in helix C between residues Gln112 and Pro116</scene>) induced by a disruption in the helical conformation, due to the Gln25 and Leu30 hydrogen bonds with four water molecules. <scene name='56/568028/Oncostatin_helix_310/1'>Helix A residues between Thr27 and Ile37</scene> take on a 3<sub>10</sub> helix conformation. With this curved structure, helices A and C enhance the compaction of the A-D and B-C parallel helix pairs, causing the core of OSM to be isolated from the solvent. | Helices A and C have breaks in the hydrogen-bonding pattern of their structure, forming tight substitute hydrogen bonds with water molecules. Indeed, it results in a kink in helix A (<scene name='56/568028/Kink_helixa/1'>and slightly in helix C between residues Gln112 and Pro116</scene>) induced by a disruption in the helical conformation, due to the Gln25 and Leu30 hydrogen bonds with four water molecules. <scene name='56/568028/Oncostatin_helix_310/1'>Helix A residues between Thr27 and Ile37</scene> take on a 3<sub>10</sub> helix conformation. With this curved structure, helices A and C enhance the compaction of the A-D and B-C parallel helix pairs, causing the core of OSM to be isolated from the solvent. | ||
This core is composed of two aromatic stacking groups, Phe56, | This core is composed of <scene name='56/568028/Helixd_aromatic/1'>two aromatic stacking groups</scene>, Phe56, Tyr173, Phe169 and Phe176 on one hand, and Phe170, Phe185 and Trp187 on the other hand. All these aromatic residues belong to helix D, except Phe56 (AB loop) and Phe70 (Helix B), highlighting the hydrophobicity of helix D. | ||
The disulphide bridge between Cys6 and Cys127 connects the N-terminal loop (Gly4-Glu9) preceding helix A to the C terminus of helix C. The second disulphide bridge between Cys49 and 167 links the start of the AB loop to the N-Terminal region of helix D. | The disulphide bridge between Cys6 and Cys127 connects the N-terminal loop (Gly4-Glu9) preceding helix A to the C terminus of helix C. The second disulphide bridge between Cys49 and 167 links the start of the AB loop to the N-Terminal region of helix D. | ||
