tRNA-modifying MiaE protein from Salmonella typhimurium is a nonheme diiron monooxygenase.

Carole Mathevon (1) , Fabien Pierrel (1) , Jean-Louis Oddou (1) , Ricardo Garcia-Serres (1) , Geneviève Blondin (1) , Jean-Marc Latour (1) , Stéphane Ménage (1) , Serge Gambarelli (2, 3) , Marc Fontecave (1) , Mohamed Atta (1)

1 LCBM - UMR 5249 - Laboratoire de Chimie et Biologie des Métaux
2 SCIB - UMR E3 - Service de Chimie Inorganique et Biologique
3 INAC - Institut Nanosciences et Cryogénie

MiaE catalyzes the posttranscriptional allylic hydroxylation of 2-methylthio-N-6-isopentenyl adenosine in tRNAs. The Salmonella typhimurium enzyme was heterologously expressed in Escherichia coli. The purified enzyme is a monomer with two iron atoms and displays activity in in vitro assays. The type and properties of the iron center were investigated by using a combination of UV-visible absorption, EPR, HYSCORE, and Mössbauer spectroscopies which demonstrated that the MiaE enzyme contains a nonheme dinuclear iron cluster, similar to that found in the hydroxylase component of methane monooxygenase. This is the first example of an enzyme from this important class of diiron monooxygenases to be involved in the hydroxylation of a biological macromolecule and the second example of a redox metalloenzyme participating in tRNA modification.

Domaines: Chimie de coordination

Carole Mathevon, Fabien Pierrel, Jean-Louis Oddou, Ricardo Garcia-Serres, Geneviève Blondin, et al.. tRNA-modifying MiaE protein from Salmonella typhimurium is a nonheme diiron monooxygenase.. Proceedings of the National Academy of Sciences of the United States of America, 2007, 104 (33), pp.13295-300. ⟨10.1073/pnas.0704338104⟩. ⟨hal-01069738⟩