title: Dual role of the molybdenum cofactor biosynthesis protein MOCS3 in tRNA thiolation and molybdenum cofactor biosynthesis in humans.
abstract: We studied two pathways that involve the transfer of persulfide sulfur in humans, molybdenum cofactor biosynthesis and tRNA thiolation. Investigations using human cells showed that the two-domain protein MOCS3 is shared between both pathways. MOCS3 has an N-terminal adenylation domain and a C-terminal rhodanese-like domain. We showed that MOCS3 activates both MOCS2A and URM1 by adenylation and a subsequent sulfur transfer step for the formation of the thiocarboxylate group at the C terminus of each protein. MOCS2A and URM1 are β-grasp fold proteins that contain a highly conserved C-terminal double glycine motif. The role of the terminal glycine of MOCS2A and URM1 was examined for the interaction and the cellular localization with MOCS3. Deletion of the C-terminal glycine of either MOCS2A or URM1 resulted in a loss of interaction with MOCS3. Enhanced cyan fluorescent protein and enhanced yellow fluorescent protein fusions of the proteins were constructed, and the fluorescence resonance energy transfer efficiency was determined by the decrease in the donor lifetime. The cellular localization results showed that extension of the C terminus with an additional glycine of MOCS2A and URM1 altered the localization of MOCS3 from the cytosol to the nucleus.
authors.affiliation: Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, Potsdam 14476, Germany.
authors.forename: Mita Mullick
authors.initials: MM
authors.lastname: Chowdhury
authors.affiliation: Institute of Chemistry, Department of Physical Chemistry, University of Potsdam, Potsdam 14476, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Dosche
authors.affiliation: Institute of Chemistry, Department of Physical Chemistry, University of Potsdam, Potsdam 14476, Germany.
authors.forename: Hans-Gerd
authors.initials: HG
authors.lastname: Löhmannsröben
authors.affiliation: Institute of Biochemistry and Biology, Department of Molecular Enzymology, University of Potsdam, Potsdam 14476, Germany. Electronic address: sleim@uni-potsdam.de.
authors.forename: Silke
authors.initials: S
authors.lastname: Leimkühler
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000502:physiology; D020816:Amino Acid Motifs; D000818:Animals; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D003067:Coenzymes / Q000096:biosynthesis* / Q000235:genetics; D003600:Cytosol / Q000378:metabolism*; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008667:Metalloproteins / Q000096:biosynthesis* / Q000235:genetics; D000090006:Molybdenum Cofactors; D009713:Nucleotidyltransferases / Q000235:genetics / Q000378:metabolism*; D017510:Protein Folding; D011621:Pteridines; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism*; D018411:Spodoptera; D013466:Sulfurtransferases / Q000235:genetics / Q000378:metabolism*; D014452:Ubiquitins / Q000235:genetics / Q000378:metabolism
chemical_list: D003067:Coenzymes; D008667:Metalloproteins; D000090006:Molybdenum Cofactors; D009713:Nucleotidyltransferases; D011621:Pteridines; D012343:RNA, Transfer; D013466:Sulfurtransferases; D014452:Ubiquitins; C529881:Urm1 protein, human; C022261:molybdopterin; C502790:MOCS3 protein, human; C085585:molybdopterin synthase