Abstract
5-Methylaminomethyl-2-selenouridine (mnm(5)Se(2)U) is found in the first position of the anticodon in certain tRNAs from bacteria, archaea and eukaryotes. This selenonucleoside is formed in Escherichia coli from the corresponding thionucleoside mnm(5)S(2)U by the monomeric enzyme YbbB. This nucleoside is present in the tRNA of Methanococcales, yet the corresponding 2-selenouridine synthase is unknown in archaea and eukaryotes. Here we report that a bipartite ybbB ortholog is present in all members of the Methanococcales. Gene deletions in Methanococcus maripaludis and in vitro activity assays confirm that the two proteins act in trans to form in tRNA a selenonucleoside, presumably mnm(5)Se(2)U. Phylogenetic data suggest a primal origin of seleno-modified tRNAs.
Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
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Amino Acid Sequence
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Animals
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Archaeal Proteins / chemistry
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Archaeal Proteins / classification
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Archaeal Proteins / genetics
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Archaeal Proteins / metabolism*
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Ligases / chemistry
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Ligases / classification
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Ligases / genetics
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Ligases / metabolism
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Methanococcus / genetics*
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Methanococcus / metabolism
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Models, Molecular
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Molecular Sequence Data
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Organoselenium Compounds / chemistry
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Organoselenium Compounds / metabolism*
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Phylogeny
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Protein Structure, Tertiary
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RNA, Transfer / classification
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RNA, Transfer / genetics
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RNA, Transfer / metabolism*
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Selenium / metabolism*
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Sequence Alignment
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Thiosulfate Sulfurtransferase / chemistry
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Thiosulfate Sulfurtransferase / genetics
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Thiosulfate Sulfurtransferase / metabolism*
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Uridine / analogs & derivatives*
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Uridine / chemistry
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Uridine / genetics
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Uridine / metabolism
Substances
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Archaeal Proteins
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Organoselenium Compounds
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5-((methylamino)methyl)-2-selenouridine
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RNA, Transfer
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Thiosulfate Sulfurtransferase
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Ligases
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Selenium
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Uridine