1EBH

OCTAHEDRAL COORDINATION AT THE HIGH AFFINITY METAL SITE IN ENOLASE; CRYSTALLOGRAPHIC ANALYSIS OF THE MG++-ENZYME FROM YEAST AT 1.9 ANGSTROMS RESOLUTION

1EBH の概要

• エントリーDOI: 10.2210/pdb1ebh/pdb
• 分子名称: ENOLASE, CHLORIDE ION, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: carbon-oxygen lyase
• 由来する生物種: Saccharomyces cerevisiae (baker's yeast)
• 細胞内の位置: Cytoplasm : P00924
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 93585.11

構造登録者

Wedekind, J.E.,Reed, G.H.,Rayment, I. (登録日: 1994-11-01, 公開日: 1995-04-27, 最終更新日: 2024-02-07)

主引用文献

Wedekind, J.E.,Reed, G.H.,Rayment, I.
Octahedral coordination at the high-affinity metal site in enolase: crystallographic analysis of the MgII--enzyme complex from yeast at 1.9 A resolution.
Biochemistry, 34:4325-4330, 1995

PubMed Abstract: 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: 7703246
DOI: 10.1021/bi00013a022

実験手法

X-RAY DIFFRACTION (1.9 Å)