tRNA-modifying MiaE protein from Salmonella typhimurium is a nonheme diiron monooxygenase.
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.
Mathevon
Carole
C
Commissariat à l'Energie Atomique/Centre National de la Recherche Scientifique/Université Joseph Fourier, Commissariat à l'Energie Atomique/Grenoble, 38054 Grenoble Cedex 09, France.
Pierrel
Fabien
F
Oddou
Jean-Louis
JL
Garcia-Serres
Ricardo
R
Blondin
Geneviève
G
Latour
Jean-Marc
JM
Ménage
Stéphane
S
Gambarelli
Serge
S
Fontecave
Marc
M
Atta
Mohamed
M
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D008969:Molecular Sequence Data; D012343:RNA, Transfer / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013056:Spectrophotometry, Ultraviolet; D014170:Transformation, Genetic
D001426:Bacterial Proteins; D012343:RNA, Transfer; D006899:Mixed Function Oxygenases