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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
13
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pubmed:dateCreated |
1995-5-10
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pubmed:abstractText |
The structure of the Mg2+ complex of yeast enolase has been determined from crystals grown in solutions of poly(ethylene glycol) at pH 8.1. Crystals belong to the space group P2(1) and have unit cell dimensions a = 72.5 A, b = 73.2 A, c = 89.1 A, and beta = 104.4 degrees. There is one dimer in the asymmetric unit. The current crystallographic R-factor is 19.0% for all recorded data to 1.9 A resolution. The electron density indicates a hexacoordinate Mg2+ at the high-affinity cation binding site. The octahedral coordination sphere consists of a meridional arrangement of three carboxylate oxygens from the side chains of Asp 246, Asp 320, and Glu 295, and three well-ordered water molecules. Octahedral coordination is the preferred geometry for alkaline earth metal ions in complexes with oxygen donor groups. In previous crystallographic studies of enolase, Zn2+ and Mg2+ complexes at the high-affinity site were reported to exist in trigonal bipyramidal coordination. This geometry was suggested to enhance the electrophilicity of the metal ion and promote rapid ligand exchange [Lebioda, L., & Stec, B. (1989) J. Am. Chem. Soc. 111, 8511-8513]. The octahedral arrangement of carboxylate and water ligands in the MgII-enolase complex determined here is most consistent with reports of the Mn2+ and Mg2+ coordination complexes of mandelate racemase and muconate lactonizing enzyme. These latter enzymes have alpha/beta-barrel folds comparable to enolase.(ABSTRACT TRUNCATED AT 250 WORDS)
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
4
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pubmed:volume |
34
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
4325-30
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:7703246-Binding Sites,
pubmed-meshheading:7703246-Crystallography, X-Ray,
pubmed-meshheading:7703246-Hydrogen-Ion Concentration,
pubmed-meshheading:7703246-Macromolecular Substances,
pubmed-meshheading:7703246-Magnesium,
pubmed-meshheading:7703246-Models, Molecular,
pubmed-meshheading:7703246-Phosphopyruvate Hydratase,
pubmed-meshheading:7703246-Protein Conformation,
pubmed-meshheading:7703246-Protein Structure, Secondary,
pubmed-meshheading:7703246-Saccharomyces cerevisiae
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pubmed:year |
1995
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pubmed:articleTitle |
Octahedral coordination at the high-affinity metal site in enolase: crystallographic analysis of the MgII--enzyme complex from yeast at 1.9 A resolution.
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pubmed:affiliation |
Institute for Enzyme Research, Graduate School, University of Wisconsin, Madison 53705, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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