1pcs
From Proteopedia
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THE 2.15 A CRYSTAL STRUCTURE OF A TRIPLE MUTANT PLASTOCYANIN FROM THE CYANOBACTERIUM SYNECHOCYSTIS SP. PCC 6803
Overview
The crystal structure of the triple mutant A42D/D47P/A63L plastocyanin, from the cyanobacterium Synechocystis sp. PCC 6803 has been determined by, Patterson search methods using the known structure of the poplar protein., Crystals of the triple mutant A42D/D47P/A63L, which are stable for days in, its oxidized form, were grown from ammonium sulfate, with the cell, constants a = b = 34.3 A and c = 111.8 A belonging to space group P3(2)21., The structure was refined using restrained crystallographic refinement to, an R-factor of 16.7% for 4070 independent reflections between 8.0 and 2.15, A with intensities greater than 2 sigma (I), with root mean square, deviations of 0.013 A and 1.63 degrees from ideal bond lengths and bond, angles, respectively. The final model comprises 727 non-hydrogen protein, atoms within 98 residues, 75 water molecules and a single copper ion. The, overall tertiary fold of Synechocystis plastocyanin consists of a compact, ellipsoidal beta-sandwich structure made up of two beta-sheets embracing a, hydrophobic core. Each sheet contains parallel and antiparallel, beta-strands. In addition to the beta-sheets, the structure contains an, alpha-helix from Pro47 to Lys54 that follows beta-strand 4. The, three-dimensional structure of Synechocystis plastocyanin is thus similar, to those reported for the copper protein isolated from eukaryotic, organisms and, in particular, from the cyanobacterium Anabaena variabilis, the only cyanobacterial plastocyanin structure available so far. The, molecule holds an hydrophobic region surrounding His87, as do other, plastocyanins, but the lack of negatively charged residues at the putative, distant remote site surrounding Tyr83 could explain why the Synechocystis, protein exhibits a collisional reaction mechanism for electron transfer to, photosystem I (PSI), which involves no formation of the transient, plastocyanin-PSI complex kinetically observed in green algae and higher, plants.
About this Structure
1PCS is a Single protein structure of sequence from Synechocystis sp. with CU as ligand. Structure known Active Site: CU. Full crystallographic information is available from OCA.
Reference
The 2.15 A crystal structure of a triple mutant plastocyanin from the cyanobacterium Synechocystis sp. PCC 6803., Romero A, De la Cerda B, Varela PF, Navarro JA, Hervas M, De la Rosa MA, J Mol Biol. 1998 Jan 16;275(2):327-36. PMID:9466912
Page seeded by OCA on Mon Nov 5 16:59:01 2007
