1yso: Difference between revisions

The three-dimensional structure of yeast copper-zinc superoxide dismutase, (CuZnSOD) has been determined in a new crystal form in space group R32 and, refined against X-ray diffraction data using difference Fourier and, restrained crystallographic refinement techniques. The unexpected result, is that the copper ion has moved approximately 1 angstrom from its, position in previously reported CuZnSOD models, the copper-imidazolate, bridge is broken, and a roughly trigonal planar ligand geometry, characteristic of Cu(I) rather than Cu(II) is revealed. Final R values for, the two nearly identical room temperature structures are 18.6% for all 19, 149 reflections in the 10.0-1.7 angstrom resolution range and 18. 2% for, 17 682 reflections (F > 2 sigma) in the 10.0-1.73 angstrom resolution, range. A third structure has been determined using X-ray data collected at, -180 degrees C. The final R value for this structure is 19.0% (R(free) =, 22.9%) for all 24 356 reflections in the 10.0-1.55 angstrom resolution, range. Virtually no change in the positions of the ligands to the zinc, center is observed in these models. The origin of the broken bridge and, altered Cu-ligand geometry is discussed.

1YSO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Candida_albicans Candida albicans] with CU1 and ZN as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Superoxide_dismutase Superoxide dismutase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.15.1.1 1.15.1.1] Structure known Active Sites: CU and ZN. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1YSO OCA].  

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