1wc7: Difference between revisions

The purification, crystallization and structure determination at 2.3 A, resolution of the complex of the pyridoxal-5'-phosphate (PLP) dependent, catalytic antibody 15A9 with a phosphopyridoxyl-L-alanine (PPL-L-alanine), substrate analogue are described. The crystal belongs to space group, P2(1), with two molecules in the asymmetric unit related by, non-crystallographic symmetry. The unit-cell parameters are a = 63.5, b =, 81.7, c = 79.3 A and beta is fortuitously 90 degrees . Refinement of the, structure converged at unacceptably high R factors. Although the, traditional analysis of intensity distribution did not indicate twinning, pseudomerohedral twinning was revealed by a newer test based on local, intensity differences [Padilla & Yeates (2003), Acta Cryst. D59, 1124-1130]. When the potential twinning operator was included in SHELX, the structure could be satisfactorily refined with a twinning fraction of, 0.46, indicating a nearly perfect hemihedrally twinned crystal. One of the, active sites is occupied by the phosphopyridoxyl-L-alanine ligand, while, one iodide ion mimics the cofactor phosphate group in the other. Four, other iodide ions are present in the structure: two are involved in, specific intermolecular contacts and two dictate the conformation of the, CDRH3 loop in each molecule.

1WC7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with IOD and PP3 as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1WC7 OCA].  

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