TY - JOUR A1 - Leimkühler, Silke A1 - Bühning, Martin A1 - Beilschmidt, Lena T1 - Shared sulfur mobilization routes for tRNA thiolation and molybdenum cofactor biosynthesis in prokaryotes and eukaryotes JF - Biomolecules N2 - Modifications of transfer RNA (tRNA) have been shown to play critical roles in the biogenesis, metabolism, structural stability and function of RNA molecules, and the specific modifications of nucleobases with sulfur atoms in tRNA are present in pro- and eukaryotes. Here, especially the thiomodifications xm(5)s(2)U at the wobble position 34 in tRNAs for Lys, Gln and Glu, were suggested to have an important role during the translation process by ensuring accurate deciphering of the genetic code and by stabilization of the tRNA structure. The trafficking and delivery of sulfur nucleosides is a complex process carried out by sulfur relay systems involving numerous proteins, which not only deliver sulfur to the specific tRNAs but also to other sulfur-containing molecules including iron-sulfur clusters, thiamin, biotin, lipoic acid and molybdopterin (MPT). Among the biosynthesis of these sulfur-containing molecules, the biosynthesis of the molybdenum cofactor (Moco) and the synthesis of thio-modified tRNAs in particular show a surprising link by sharing protein components for sulfur mobilization in pro- and eukaryotes. KW - tRNA KW - molybdenum cofactor KW - persulfide KW - thiocarboxylate KW - thionucleosides KW - sulfurtransferase KW - l-cysteine desulfurase Y1 - 2017 U6 - https://doi.org/10.3390/biom7010005 SN - 2218-273X VL - 7 IS - 1 PB - MDPI CY - Basel ER - TY - JOUR A1 - Leimkühler, Silke T1 - Shared function and moonlighting proteins in molybdenum cofactor biosynthesis JF - Biological chemistry N2 - The biosynthesis of the molybdenum cofactor (Moco) is a highly conserved pathway in bacteria, archaea and eukaryotes. The molybdenum atom in Moco-containing enzymes is coordinated to the dithiolene group of a tricyclic pyranopterin monophosphate cofactor. The biosynthesis of Moco can be divided into three conserved steps, with a fourth present only in bacteria and archaea: (1) formation of cyclic pyranopterin monophosphate, (2) formation of molybdopterin (MPT), (3) insertion of molybdenum into MPT to form Mo-MPT, and (4) additional modification of Mo-MPT in bacteria with the attachment of a GMP or CMP nucleotide, forming the dinucleotide variants of Moco. While the proteins involved in the catalytic reaction of each step of Moco biosynthesis are highly conserved among the Phyla, a surprising link to other cellular pathways has been identified by recent discoveries. In particular, the pathways for FeS cluster assembly and thio-modifications of tRNA are connected to Moco biosynthesis by sharing the same protein components. Further, proteins involved in Moco biosynthesis are not only shared with other pathways, but additionally have moonlighting roles. This review gives an overview of Moco biosynthesis in bacteria and humans and highlights the shared function and moonlighting roles of the participating proteins. KW - FeS cluster KW - molybdenum cofactor KW - molybdo-enzymes KW - moonlighting KW - sulfur transfer KW - tRNA thiolation Y1 - 2017 U6 - https://doi.org/10.1515/hsz-2017-0110 SN - 1431-6730 SN - 1437-4315 VL - 398 SP - 1009 EP - 1026 PB - De Gruyter CY - Berlin ER -