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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1995-5-10
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)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4325-30
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
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.
pubmed:affiliation
Institute for Enzyme Research, Graduate School, University of Wisconsin, Madison 53705, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.