The isolation, purification, and preliminary crystallographic characterization of UDP-galactose-4-epimerase from Escherichia coli |
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Authors: | A J Bauer I Rayment P A Frey H M Holden |
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Institution: | Institute for Enzyme Research, Graduate School, University of Wisconsin-Madison 53705. |
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Abstract: | Uridine diphosphogalactose-4-epimerase from E. coli has been crystallized in a form suitable for a high-resolution X-ray crystallographic structural analysis. The enzyme complexed with a substrate analogue, uridine diphosphobenzene (UDP-benzene), crystallizes readily using polyethylene glycol 8000 as the precipitant. The crystals belong to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions, a = 76.3 A, b = 83.1 A, and c = 132.1 A. Based on still setting photographs, the crystals diffract to a nominal resolution of 2.3 A and are stable in the X-ray beam. The enzyme used in these experiments was produced by a new expression system and a modified purification scheme. |
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Keywords: | X-ray crystallography galactose metabolism nucleotide binding nonstereospecific hydride transfer protein structure |
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