Insulin: Difference between revisions
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<scene name='82/821037/Ribbon/1'>Mature insulin</scene> contains two chains, A <jmol> | <scene name='82/821037/Ribbon/1'>Mature insulin</scene> contains two chains, A <jmol> | ||
<jmolLink> | <jmolLink> | ||
<script> select *:A; selectionHalos ON; delay 0.5;selectionHalos OFF; </script> | <script> select backbone and *:A; selectionHalos ON; delay 0.5;selectionHalos OFF; </script> | ||
<text>(☼)</text> | <text>(☼)</text> | ||
</jmolLink> | </jmolLink> | ||
</jmol> and B <jmol> | </jmol> and B <jmol> | ||
<jmolLink> | <jmolLink> | ||
<script> select *:B; selectionHalos ON; delay 0.5;selectionHalos OFF; </script> | <script> select backbone *:B; selectionHalos ON; delay 0.5;selectionHalos OFF; </script> | ||
<text>(☼)</text> | <text>(☼)</text> | ||
</jmolLink> | </jmolLink> | ||
| Line 121: | Line 121: | ||
Cryo-electronmicroscopy studies have shown a [http://proteopedia.org/wiki/images/0/05/LambdaTee.gif Λ to T transition] when insulin binds. One structure resolves four <scene name='82/821037/Spacefilling/5'>insulin binding sites</scene> (1, 1', 2, 2') per receptor dimer<ref name="ecto">DOI:10.1101/679233 </ref> (coordinates not yet available). Contacts with insulin are distinct in site 1 vs. site 2, as are the conformations of insulin<ref>PMID:25092300</ref>. For comparison to the initial scene, here is another view of the <scene name='82/821037/Ribbon/2'>contact residues</scene>. | Cryo-electronmicroscopy studies have shown a [http://proteopedia.org/wiki/images/0/05/LambdaTee.gif Λ to T transition] when insulin binds. One structure resolves four <scene name='82/821037/Spacefilling/5'>insulin binding sites</scene> (1, 1', 2, 2') per receptor dimer<ref name="ecto">DOI:10.1101/679233 </ref> (coordinates not yet available). Contacts with insulin are distinct in site 1 vs. site 2, as are the conformations of insulin<ref>PMID:25092300</ref>. For comparison to the initial scene, here is another view of the <scene name='82/821037/Ribbon/2'>contact residues</scene>. | ||
<scene name='82/821037/Receptor_bound/1'>Binding sites 1 and 1'</scene> had already been characterized in previous structures<ref>PMID:29512653</ref><ref name="gutmann"/>. Insulin makes contacts with both the N-terminal domain and the CT alpha helix, structural elements that are far apart in the unliganded conformation. Thus, binding of insulin in site 1 requires a large structural rearrangement that activates the tyrosine kinase activity of the endodomain by bringing the two kinase domains close for autophosphorylation. | <scene name='82/821037/Receptor_bound/1'>Binding sites 1 and 1'</scene> had already been characterized in previous structures<ref>PMID:29512653</ref><ref name="gutmann"/>. Insulin makes contacts with both the N-terminal domain <jmol> | ||
<jmolLink> | |||
<script> select *:A; selectionHalos ON; delay 0.5;selectionHalos OFF; </script> | |||
<text>(☼)</text> | |||
</jmolLink> | |||
</jmol> and the CT alpha helix <jmol> | |||
<jmolLink> | |||
<script> select *:P; selectionHalos ON; delay 0.5;selectionHalos OFF; </script> | |||
<text>(☼)</text> | |||
</jmolLink> | |||
</jmol>, structural elements that are far apart in the unliganded conformation. Thus, binding of insulin in site 1 requires a large structural rearrangement that activates the tyrosine kinase activity of the endodomain by bringing the two kinase domains close for autophosphorylation. | |||
</StructureSection> | </StructureSection> | ||
