Affiliation:
1. Institut für Biologie II, Albert-Ludwigs-Universität, Freiburg
2. Mikrobiologie, Department für Biologie I, Ludwig-Maximilians-Universität, Munich, Germany
Abstract
ABSTRACT
The sulfate-reducing bacterium
Desulfococcus multivorans
uses various aromatic compounds as sources of cell carbon and energy. In this work, we studied the initial steps in the aromatic metabolism of this strictly anaerobic model organism. An ATP-dependent benzoate coenzyme A (CoA) ligase (AMP plus PP
i
forming) composed of a single 59-kDa subunit was purified from extracts of cells grown on benzoate. Specific activity was highest with benzoate and some benzoate derivatives, whereas aliphatic carboxylic acids were virtually unconverted. The N-terminal amino acid sequence showed high similarities with benzoate CoA ligases from
Thauera aromatica
and
Azoarcus evansii
. When cultivated on benzoate, cells strictly required selenium and molybdenum, whereas growth on nonaromatic compounds, such as cyclohexanecarboxylate or lactate, did not depend on the presence of the two trace elements. The growth rate on benzoate was half maximal with 1 nM selenite present in the growth medium. In molybdenum- and/or selenium-depleted cultures, growth on benzoate could be induced by addition of the missing trace elements. In extracts of cells grown on benzoate in the presence of [
75
Se]selenite, three radioactively labeled proteins with molecular masses of ∼100, 30, and 27 kDa were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. The 100- and 30-kDa selenoproteins were 5- to 10-fold induced in cells grown on benzoate compared to cells grown on lactate. These results suggest that the dearomatization process in
D. multivorans
is not catalyzed by the ATP-dependent Fe-S enzyme benzoyl-CoA reductase as in facultative anaerobes but rather involves unknown molybdenum- and selenocysteine-containing proteins.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference47 articles.
1. Auburger, G., and J. Winter. 1992. Purification and characterization of benzoyl-CoA ligase from a syntrophic, benzoate-degrading, anaerobic mixed culture. Appl. Microbiol. Biotechnol.37:789-795.
2. Axley, M. J., A. Böck, and T. C., Stadtman. 1991. Catalytic properties of an Escherichia coli formate dehydrogenase mutant in which sulfur replaces selenium. Proc. Natl. Acad. Sci. USA88:8450-8454.
3. Topological Analysis of the Aerobic Membrane-Bound Formate Dehydrogenase of
Escherichia coli
4. Berry, M. J., J. D. Kieffer, and P. R. Larsen. 1991. Evidence that cysteine, not selenocysteine, is in the catalytic site of type II iodothyronine deiodinase. Endocrinology129:550-552.
5. Boll, M., D. Laempe, W. Eisenreich, A. Bacher, T. Mittelberger, J. Heinze, and G. Fuchs. 2000. Non-aromatic products from anoxic conversion of benzoyl-CoA with benzoyl-CoA reductase and cyclohexa-1,5-diene-1-carbonyl-CoA hydratase. J. Biol. Chem.275:21889-21895.
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