Sandbox Reserved 1167: Difference between revisions

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However, one particular difference between class A receptors and class B receptors is an inward shift of the intracellular component of Helix VII. In class A receptors this inward shift is instrumental in receptor activation, yet in class B receptors it remains unclear what role this shift plays.  
However, one particular difference between class A receptors and class B receptors is an inward shift of the intracellular component of Helix VII. In class A receptors this inward shift is instrumental in receptor activation, yet in class B receptors it remains unclear what role this shift plays.  
    
    
In contrast to class A glucagon receptors which have a [https://en.wikipedia.org/wiki/Proline proline] kink, in all  [https://en.wikipedia.org/wiki/Secretin_receptor_family secretin-like class B glucagon receptors] a [https://en.wikipedia.org/wiki/Glycine Glycine] at position 393 in Helix VII allows for a <scene name='72/721537/Gly_393_helical_bend/1'>helical bend</scene>. This glycine helical bend is fully [https://en.wikipedia.org/wiki/Conserved_sequence conserved] in all secretin-like class B receptors and is an important part of the FQGxxVxxYCF [https://en.wikipedia.org/wiki/Sequence_motif motif].
In contrast to class A glucagon receptors which have a [https://en.wikipedia.org/wiki/Proline proline] kink, in all  [https://en.wikipedia.org/wiki/Secretin_receptor_family secretin-like class B glucagon receptors] a [https://en.wikipedia.org/wiki/Glycine Glycine] at position 393 in Helix VII allows for a <scene name='72/721537/Gly_393_helical_bend/1'>helical bend</scene>. This glycine helical bend is fully [https://en.wikipedia.org/wiki/Conserved_sequence conserved] in all secretin-like class B receptors.


Another important structural component found in all secretin-like class B receptors are the two conserved [https://en.wikipedia.org/wiki/Salt_bridge_%28protein_and_supramolecular%29 salt bridges] found between [https://en.wikipedia.org/wiki/Arginine Arg] 346 and [https://en.wikipedia.org/wiki/Glutamic_acid Glu] 406 and Arg 173 and Glu 406 [[Image:Salt Bridge Interactions.png | 250 px|right|thumb|Glu 406 Salt Bridges]]. These salt bridges are a distinct feature of class B receptors only because their interaction results in the distinct stalk found only in class B receptors<ref name ='structure_article'>PMID:23863937</ref>.   
Another important structural component found in all secretin-like class B receptors are the two conserved [https://en.wikipedia.org/wiki/Salt_bridge_%28protein_and_supramolecular%29 salt bridges] found between [https://en.wikipedia.org/wiki/Arginine Arg] 346 and [https://en.wikipedia.org/wiki/Glutamic_acid Glu] 406 and Arg 173 and Glu 406 [[Image:Salt Bridge Interactions.png | 250 px|right|thumb|Glu 406 Salt Bridges]]. These salt bridges are a distinct feature of class B receptors only because their interaction results in the distinct stalk found only in class B receptors<ref name ='structure_article'>PMID:23863937</ref>.