The putative tRNA 2-thiouridine synthetase Ncs6 is an essential sulfur carrier in Methanococcus maripaludis

Thiolation of carbon-2 of uridine located in the first position of the anticodons of tRNA(UUG)(Gln), tRNA(UUC)(Gln), and tRNA(UUU)(Lys) is a conserved RNA modification event requiring the 2-thiouridine synthetase Ncs6/Ctu1 in archaea and eukaryotes. Ncs6/Ctu1 activates uridine by adenylation, but its role in sulfur transfer is unclear. Here we show that Mmp1356, the Ncs6/Ctu1 homolog in the archaeon Methanococcus maripaludis, forms a persulfide enzyme adduct with an active site cysteine; this suggests that Mmp1356 directly participates in sulfur transfer as a persulfide carrier. Transposon mutagenesis shows that Mmp1356 is likely to be an essential protein. Structured summary of protein interactions: MMP1356 physically interacts with MMP0161, MMP0680, MMP1357 and MMP1322 by pull down (View interaction) (C) 2014 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.