title: Spectroscopic studies on Arabidopsis ETHE1, a glyoxalase II-like protein.
abstract: ETHE1 (ethylmalonic encephalopathy protein 1) is a beta-lactamase fold-containing protein that is essential for the survival of a range of organisms. In spite of the apparent importance of this enzyme, very little is known about its function or biochemical properties. In this study Arabidopsis ETHE1 was over-expressed and purified and shown to bind tightly to 1.2+/-0.2 equivalents of iron. (1)H NMR and EPR studies demonstrate that the predominant oxidation state of Fe in ETHE1 is Fe(II), and NMR studies confirm that two histidines are bound to Fe(II). EPR studies show that there is no antiferromagnetically coupled Fe(III)Fe(II) center in ETHE1. Gel filtration studies reveal that ETHE1 is a dimer in solution, which is consistent with previous crystallographic studies. Although very similar in terms of amino acid sequence to glyoxalase II, ETHE1 exhibits no thioester hydrolase activity, and activity screening assays reveal that ETHE1 exhibits low level esterase activity. Taken together, ETHE1 is a novel, mononuclear Fe(II)-containing member of the beta-lactamase fold superfamily.
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, United States.
authors.forename: Meghan M
authors.initials: MM
authors.lastname: Holdorf
authors.forename: Brian
authors.initials: B
authors.lastname: Bennett
authors.forename: Michael W
authors.initials: MW
authors.lastname: Crowder
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Makaroff
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005296:Ferrous Compounds / Q000737:chemistry; D007501:Iron / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008345:Manganese / Q000378:metabolism; D010084:Oxidation-Reduction; D011485:Protein Binding; D013869:Thiolester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015032:Zinc / Q000378:metabolism; D000099301:Hydroxyacylglutathione Hydrolase
chemical_list: D029681:Arabidopsis Proteins; D005296:Ferrous Compounds; D007501:Iron; D008345:Manganese; D013869:Thiolester Hydrolases; D015032:Zinc; D000099301:Hydroxyacylglutathione Hydrolase