@misc{LeimkuehlerBuehningBeilschmidt2017, author = {Leimk{\"u}hler, Silke and B{\"u}hning, Martin and Beilschmidt, Lena}, title = {Shared sulfur mobilization routes for tRNA thiolation and molybdenum cofactor biosynthesis in prokaryotes and eukaryotes}, series = {Biomolecules}, volume = {7}, journal = {Biomolecules}, number = {1}, publisher = {MDPI}, address = {Basel}, issn = {2218-273X}, doi = {10.3390/biom7010005}, pages = {20}, year = {2017}, abstract = {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.}, language = {en} } @misc{Leimkuehler2017, author = {Leimk{\"u}hler, Silke}, title = {Shared function and moonlighting proteins in molybdenum cofactor biosynthesis}, series = {Biological chemistry}, volume = {398}, journal = {Biological chemistry}, publisher = {De Gruyter}, address = {Berlin}, issn = {1431-6730}, doi = {10.1515/hsz-2017-0110}, pages = {1009 -- 1026}, year = {2017}, abstract = {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.}, language = {en} } @misc{LeimkuehlerIobbiNivol2016, author = {Leimk{\"u}hler, Silke and Iobbi-Nivol, Chantal}, title = {Bacterial molybdoenzymes: old enzymes for new purposes}, series = {FEMS microbiology reviews}, volume = {40}, journal = {FEMS microbiology reviews}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0168-6445}, doi = {10.1093/femsre/fuv043}, pages = {1 -- 18}, year = {2016}, abstract = {Molybdoenzymes are widespread in eukaryotic and prokaryotic organisms where they play crucial functions in detoxification reactions in the metabolism of humans and bacteria, in nitrate assimilation in plants and in anaerobic respiration in bacteria. To be fully active, these enzymes require complex molybdenum-containing cofactors, which are inserted into the apoenzymes after folding. For almost all the bacterial molybdoenzymes, molybdenum cofactor insertion requires the involvement of specific chaperones. In this review, an overview on the molybdenum cofactor biosynthetic pathway is given together with the role of specific chaperones dedicated for molybdenum cofactor insertion and maturation. Many bacteria are involved in geochemical cycles on earth and therefore have an environmental impact. The roles of molybdoenzymes in bioremediation and for environmental applications are presented.This review gives an overview of the diverse mechanisms leading to the insertion of the different forms of the molybdenum cofactor into the respective target enzymes and summarizes the roles of different molybdoenzymes in the environment.This review gives an overview of the diverse mechanisms leading to the insertion of the different forms of the molybdenum cofactor into the respective target enzymes and summarizes the roles of different molybdoenzymes in the environment.}, language = {en} }