1XM8

X-RAY STRUCTURE OF GLYOXALASE II FROM ARABIDOPSIS THALIANA GENE AT2G31350

Summary for 1XM8

• Entry DOI: 10.2210/pdb1xm8/pdb
• Descriptor: glyoxalase II, ZINC ION, FE (III) ION, ... (6 entities in total)
• Functional Keywords: structural genomics, protein structure initiative, psi, cesg, at2g31350, metallo-hydrolase, zinc/iron binuclear center, b-lactamase fold, thioester hydrolase, mitochondrial isozyme, center for eukaryotic structural genomics, hydrolase
• Biological source: Arabidopsis thaliana (thale cress)
• Total number of polymer chains: 2
• Total formula weight: 56910.93

Authors

Wesenberg, G.E.,Smith, D.W.,Phillips Jr., G.N.,Bitto, E.,Bingman, C.A.,Allard, S.T.M.,Center for Eukaryotic Structural Genomics (CESG) (deposition date: 2004-10-01, release date: 2004-10-12, Last modification date: 2024-02-14)

Primary citation

Marasinghe, G.P.,Sander, I.M.,Bennett, B.,Periyannan, G.,Yang, K.W.,Makaroff, C.A.,Crowder, M.W.
Structural studies on a mitochondrial glyoxalase II.
J.Biol.Chem., 280:40668-40675, 2005

PubMed Abstract: Glyoxalase 2 is a beta-lactamase fold-containing enzyme that appears to be involved with cellular chemical detoxification. Although the cytoplasmic isozyme has been characterized from several organisms, essentially nothing is known about the mitochondrial proteins. As a first step in understanding the structure and function of mitochondrial glyoxalase 2 enzymes, a mitochondrial isozyme (GLX2-5) from Arabidopsis thaliana was cloned, overexpressed, purified, and characterized using metal analyses, EPR and (1)H NMR spectroscopies, and x-ray crystallography. The recombinant enzyme was shown to bind 1.04 +/- 0.15 eq of iron and 1.31 +/- 0.05 eq of Zn(II) and to exhibit k(cat) and K(m) values of 129 +/- 10 s(-1) and 391 +/- 48 microm, respectively, when using S-d-lactoylglutathione as the substrate. EPR spectra revealed that recombinant GLX2-5 contains multiple metal centers, including a predominant Fe(III)Z-n(II) center and an anti-ferromagnetically coupled Fe(III)Fe(II) center. Unlike cytosolic glyoxalase 2 from A. thaliana, GLX2-5 does not appear to specifically bind manganese. (1)H NMR spectra revealed the presence of at least eight paramagnetically shifted resonances that arise from protons in close proximity to a Fe(III)Fe(II) center. Five of these resonances arose from solvent-exchangeable protons, and four of these have been assigned to NH protons on metal-bound histidines. A 1.74-A resolution crystal structure of the enzyme revealed that although GLX2-5 shares a number of structural features with human GLX2, several important differences exist. These data demonstrate that mitochondrial glyoxalase 2 can accommodate a number of different metal centers and that the predominant metal center is Fe(III)Zn(II).

PubMed: 16227621
DOI: 10.1074/jbc.M509748200

Experimental method

X-RAY DIFFRACTION (1.74 Å)