Sandbox 143: Difference between revisions
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===Residue distribution=== | ===Residue distribution=== | ||
Plastocyanin extracted from a Green Alga, Enteromorpha prolifera, has a '''β-sandwich structure''' as a slightly flattened cylinder with approximate dimensions 40 Å × 32 Å × 28 Å[http://www.nature.com/nature/journal/v272/n5651/abs/272319a0.html Nature]. This β-sandwich is composed of two β-sheets (I and II) separated by a hydrophobic coreTurns on the two β-sheets occur between residues 42 to 45 and 47 to 50. | Plastocyanin extracted from a Green Alga, Enteromorpha prolifera, has a '''β-sandwich structure''' as a slightly flattened cylinder with approximate dimensions 40 Å × 32 Å × 28 Å [http://www.nature.com/nature/journal/v272/n5651/abs/272319a0.html Nature]. This β-sandwich is composed of two β-sheets (I and II) separated by a hydrophobic coreTurns on the two β-sheets occur between residues 42 to 45 and 47 to 50. | ||
Seven strands (1 to 4 and 6 to 8) of the polypeptide backbone have substantial β character and contribute to the β-sheets. The 5 strand has no β character and formed a helical segment. | Seven strands (1 to 4 and 6 to 8) of the polypeptide backbone have substantial β character and contribute to the β-sheets. The 5 strand has no β character and formed a helical segment. | ||
The symmetry of this molecule related on an van der Waals’ bond on the northern loop between strands 3 and 4 the side-chain of Pro36 which contacts Gln 68. | The symmetry of this molecule related on an van der Waals’ bond on the northern loop between strands 3 and 4 the side-chain of Pro36 which contacts Gln 68. | ||
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===Ligand=== | ===Ligand=== | ||
[[Image:600px-Plastocyanin_copper_binding.jpg | thumb | right | Plastocyanin copper binding site]] | [[Image:600px-Plastocyanin_copper_binding.jpg | thumb | right | Plastocyanin copper binding site]] | ||
Ion copper in the oxidized state 2 + is localized at one end of the molecule, 6 Å below the surface. The copper atom is in the core of a hydrophobic patch composed of residues His-37, Cys-84, His-87 and Met-92. This copper binding site has a distorted trigonal pyramidal shape. The base of the pyramide is composed of one sulfur from a cysteine and two nitrogen atoms from two different histidins and the apex is formed by one sulfur from a methionin. The distortion occurs on the bond between the copper and the sulfur atom. | Ion copper in the oxidized state 2 + is localized at one end of the molecule, 6 Å below the surface. The copper atom is in the core of a hydrophobic patch composed of residues His-37, Cys-84, His-87 and Met-92. This copper binding site has a distorted trigonal pyramidal shape. The base of the pyramide is composed of one sulfur from a cysteine and two nitrogen atoms from two different histidins and the apex is formed by one sulfur from a methionin. The distortion occurs on the bond between the copper and the sulfur atom. | ||
