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Wayne Decatur, Student, Mathilde Bichelberger

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 <Structure load='7PCY' size='500' frame='true' align='right' caption='Protein name : plastocyanin; Organism : Enteromorpha prolifera; Taxonomie : Eukaryota › Viridiplantae › Chlorophyta › Ulvophyceae › Ulvales › Ulvaceae › Ulva; Resolution : 1.80 &Aring;; Poids : 10,500 D' scene='Insert optional scene name here' | left />
+===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 . This β-sandwich  is composed of two β-sheets (I and II) separated by a hydrophobic core.Turns 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.
+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.
+This plastocyanin included an important '''“acidic patch”''' which is localized between residues 59 to 61 and 42 to 45. This acidic patch is significant in electron transfer namely facilitating electrostatic recognition of  her redox partner.( see part Role in Photosynthesis )
+This molecule has 111 solvent sites and 16 intermolecular hydrogen bonds.
-===Residue distribution===
 ===Ligand===
 [[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.
+Plastocyanin in the reduced form with ion copper in the form +1 has a different copper binding site shape. His-87 a residue of the hydrophobic patch will be protonated  and the copper site has a trigonal planar structure.
 =='''Role in Photosynthesis'''==
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 :2.Colman, P.M., Freeman, H.C., Guss, J.M., Murata, M., Norris, V.A., Ramshaw, J.A.M. and Venkatappa M.P.(1978)Nature (Lond.) '''272''', 319-324. [[http://www.nature.com/nature/journal/v272/n5651/abs/272319a0.html]]
 :3.Simpson J. R., Moritz, L.R., Nice, E.C., Grego, B. and Yoshizak, F. (1986)Complete amino acid sequence of plastocyanin from  a green alga, Enteromorpha prolifera, Eur.J. Biochem. '''157''', 497-506. [[http://onlinelibrary.wiley.com/doi/10.1111/j.1432-1033.1986.tb09694.x/pdf]]
-:4.Cookson, D. J., Hayes, M. T. and Wright, P. E. (1980) Nature (Lond.) '''283''', 682-683.
+:4.Cookson, D. J., Hayes, M. T. and Wright, P. E. (1980) Nature (Lond.) '''283''', 682-683. [[http://www.springerlink.com/content/g5n15867765m52h4/]]
-:5.Handford, P. M., Hill, H. A. O., Lee, R. W.-K., Henderson, R.A. and Sykes, A. G. (1980) J. Inorg. Biochem. '''13''', 83-88.
+:5.Handford, P. M., Hill, H. A. O., Lee, R. W.-K., Henderson, R.A. and Sykes, A. G. (1980) J. Inorg. Biochem. '''13''', 83-88.[[http://www.springerlink.com/content/v429428w64w5vv5v/]]
 :6.Chothia and Lesk, 1982; Guss and Freeman, 1983.