1be4: Difference between revisions

The biochemical and structural properties of bovine retinal nucleoside, diphosphate kinase were investigated. The enzyme showed two polypeptides, of approximately 17.5 and 18.5 kDa on SDS-PAGE, while isoelectric focusing, revealed seven to eight proteins with a pI range of 7.4-8.2. Sedimentation, equilibrium yielded a molecular mass of 96 +/- 2 kDa for the enzyme., Carbohydrate analysis revealed that both polypeptides contained Gal, Man, GlcNAc, Fuc, and GalNac saccharides. Like other nucleoside diphosphate, kinases, the retinal enzyme showed substantial differences in the Km, values for various di- and triphosphate nucleotides. Immunogold labeling, of bovine retina revealed that the enzyme is localized on both the, membranes and in the cytoplasm. Screening of a retinal cDNA library, yielded full-length clones encoding two distinct isoforms (NBR-A and, NBR-B). Both isoforms were overexpressed in Escherichia coli and their, biochemical properties compared with retinal NDP-kinase. The structures of, NBR-A and NBR-B were determined by X-ray crystallography in the presence, of guanine nucleotide(s). Both isoforms are hexameric, and the fold of the, monomer is similar to other nucleoside diphosphate kinase structures. The, NBR-A active site contained both a cGMP and a GDP molecule each bound at, half occupancy while the NBR-B active site contained only cGMP.

1BE4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with PCG as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Nucleoside-diphosphate_kinase Nucleoside-diphosphate kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.4.6 2.7.4.6] Structure known Active Site: NUL. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1BE4 OCA].  

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