Download MendeleyCrystal structure and biochemical studies of Brucella melitensis 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase
Kang, X.S., Zhao, Y., Jiang, D.H., Li, X.M., Wang, X.P., Wu, Y., Chen, Z.L., Zhang, X.C.(2014) Biochem Biophys Res Commun 446: 965-970
- PubMed: 24657441
- DOI: https://doi.org/10.1016/j.bbrc.2014.03.045
- Primary Citation of Related Structures:
4PR3 - PubMed Abstract:
The prokaryotic 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTAN) catalyzes the irreversible cleavage of the glycosidic bond in 5'-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 2.6 Å 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.
Organizational Affiliation:
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
