Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10755603 | Biochemical and Biophysical Research Communications | 2014 | 6 Pages |
Abstract
The prokaryotic 5â²-methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTAN) catalyzes the irreversible cleavage of the glycosidic bond in 5â²-methylthioadenosine (MTA) and S-adenosylhomocysteine (SAH), a process that plays a key role in several metabolic pathways. Its absence in all mammalian species has implicated this enzyme as a promising target for antimicrobial drug design. Here, we report the crystal structure of BmMTAN in complex with its product adenine at a resolution of 2.6Â Ã
determined by single-wavelength anomalous dispersion method. 11 key residues were mutated for kinetic characterization. Mutations of Tyr134 and Met144 resulted in the largest overall increase in Km, whereas mutagenesis of residues Glu18, Glu145 and Asp168 completely abolished activity. Glu145 and Asp168 were identified as active site residues essential for catalysis. The catalytic mechanism and implications of this structure for broad-based antibiotic design are discussed.
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Biochemistry, Genetics and Molecular Biology
Biochemistry
Authors
Xusheng Kang, Yan Zhao, Daohua Jiang, Xuemei Li, Xianping Wang, Yan Wu, Zeliang Chen, Xuejun C. Zhang,