Sandbox 167: Difference between revisions
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{{STRUCTURE_1vpr| PDB=1vpr | SCENE= }} | {{STRUCTURE_1vpr| PDB=1vpr | SCENE= }} | ||
<scene name='colorSTRUCTURE'>structure</scene> | |||
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Composed of residues 868-1218, domain 3 (D3) also consists of a 20aa c domain, but said region was unable to be solved due to high disorder in the region. Composed of 7 α-helices and 16 β-strands, D3 is further organized into subdomains. The main portion of the enzyme appears to be a β-barrel structure composed of 10 antiparrallel strands connected via a Gly rich sequence to a 3 helix bundle. This bundle is stabilized by a hydrophobic core region as well as a multitude of H-bonding patterns. The β-barrel structure actually has some homology with the human muscle fatty acid binding protein (m-FABP, pdb= 1HMT). This, and other related proteins, form a "β-clam" subdomain structure for binding of hydrophobic molecules. However, other known β-clam structures do not possess enzymatic activity. | Composed of residues 868-1218, domain 3 (D3) also consists of a 20aa c domain, but said region was unable to be solved due to high disorder in the region. Composed of 7 α-helices and 16 β-strands, D3 is further organized into subdomains. The main portion of the enzyme appears to be a β-barrel structure composed of 10 antiparrallel strands connected via a Gly rich sequence to a 3 helix bundle. This bundle is stabilized by a hydrophobic core region as well as a multitude of H-bonding patterns. The β-barrel structure actually has some homology with the human muscle fatty acid binding protein (m-FABP, pdb= 1HMT). This, and other related proteins, form a "β-clam" subdomain structure for binding of hydrophobic molecules. However, other known β-clam structures do not possess enzymatic activity. | ||
Cropped Pymol image of 1vpr highlighting the β-barrel structure and tri-helix. The four histidine residues implied in pH-dependant activity regulation are highlighted in pink. | |||
[[Image:Structure_trihelix_barrel.jpg ]] | |||
Note the position of the tri-helix in front of the β-barrel opening, blocking substrate entry. Under pH 8, the protonation states of the four histidines are thought to drive a conformational change that opens and expands the β-barrel. | |||