User:Amy Kerzmann/Sandbox 2

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(Voltage-gated Potassium Channel)
(Voltage-gated Potassium Channel)
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== Voltage-gated Potassium Channel ==
== Voltage-gated Potassium Channel ==
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{{STRUCTURE_3cs9| PDB=1bl8 | SCENE=User:Amy_Kerzmann/Sandbox_2/Potassium_ions/2}}
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{{STRUCTURE_3cs9| PDB=1bl8 | SCENE=User:Amy_Kerzmann/Sandbox_2/Potassium_ions/4}}
'''Backgound'''
'''Backgound'''
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The central core of this protein is comprised of eight helices, two from each monomeric subunit. Since each <scene name='User:Amy_Kerzmann/Sandbox_2/Chain_a/1'>monomer</scene> has the same orientation in the membrane, the protein has a four-fold rotational symmetry when viewed from the membrane surface. As a result, each of the channel-lining residues appears as a ring of four identical sidechains. This principle is represented by the conserved <scene name='User:Amy_Kerzmann/Sandbox_2/Tyrosine_symmetry/1'>tyrosine</scene> residues that function as selectivity filters within the cavity. Additional <scene name='User:Amy_Kerzmann/Sandbox_2/Aspartate_symmetry/1'>aspartate</scene> and <scene name='User:Amy_Kerzmann/Sandbox_2/Threonine_symmetry/2'>threonine</scene> residues line the channel. Looking at a <scene name='User:Amy_Kerzmann/Sandbox_2/Channel-lining_residues/1'>composite</scene> of these residues, one can see that some hydrophobic patches remain within the cavity.
The central core of this protein is comprised of eight helices, two from each monomeric subunit. Since each <scene name='User:Amy_Kerzmann/Sandbox_2/Chain_a/1'>monomer</scene> has the same orientation in the membrane, the protein has a four-fold rotational symmetry when viewed from the membrane surface. As a result, each of the channel-lining residues appears as a ring of four identical sidechains. This principle is represented by the conserved <scene name='User:Amy_Kerzmann/Sandbox_2/Tyrosine_symmetry/1'>tyrosine</scene> residues that function as selectivity filters within the cavity. Additional <scene name='User:Amy_Kerzmann/Sandbox_2/Aspartate_symmetry/1'>aspartate</scene> and <scene name='User:Amy_Kerzmann/Sandbox_2/Threonine_symmetry/2'>threonine</scene> residues line the channel. Looking at a <scene name='User:Amy_Kerzmann/Sandbox_2/Channel-lining_residues/1'>composite</scene> of these residues, one can see that some hydrophobic patches remain within the cavity.
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<applet load='User:Amy_Kerzmann/Sandbox_2/Potassium_ions/3' size='300' frame='true' align='right' caption='Insert caption here' />
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<applet load='1bl8' size='300' frame='true' align='left' caption='Insert caption here' />
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Revision as of 21:11, 24 September 2009

Voltage-gated Potassium Channel

Template:STRUCTURE 3cs9 Backgound


This crystal structure illuminated the principles of ion selectivity when it was solved in 1998.[1] To further demonstrate the importance of this structure, the 2003 Nobel Prize in Chemistry was awarded to the principal investigator, Roderick MacKinnon.


Channel Structure:


The potassium channel is a homotetramer, meaning that it is comprised of four identical .


The central core of this protein is comprised of eight helices, two from each monomeric subunit. Since each has the same orientation in the membrane, the protein has a four-fold rotational symmetry when viewed from the membrane surface. As a result, each of the channel-lining residues appears as a ring of four identical sidechains. This principle is represented by the conserved residues that function as selectivity filters within the cavity. Additional and residues line the channel. Looking at a of these residues, one can see that some hydrophobic patches remain within the cavity.

Insert caption here

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Channel Function:


Here's how it works.


References


  1. Doyle DA, Morais Cabral J, Pfuetzner RA, Kuo A, Gulbis JM, Cohen SL, Chait BT, MacKinnon R. The structure of the potassium channel: molecular basis of K+ conduction and selectivity. Science. 1998 Apr 3;280(5360):69-77. PMID:9525859

Proteopedia Page Contributors and Editors (what is this?)

Amy Kerzmann, Jaime Prilusky

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