The enzyme transfers sulfur to form a thiocarboxylate moiety on the C-terminal glycine of the small subunit of EC 2.8.1.12, molybdopterin synthase. In the human, the reaction is catalysed by the rhodanese-like C-terminal domain (cf. EC 2.8.1.1) of the MOCS3 protein, a bifunctional protein that also contains EC 2.7.7.80, molybdopterin-synthase adenylyltransferase, at the N-terminal domain.
The enzyme transfers sulfur to form a thiocarboxylate moiety on the C-terminal glycine of the small subunit of EC 2.8.1.12, molybdopterin synthase. In the human, the reaction is catalysed by the rhodanese-like C-terminal domain (cf. EC 2.8.1.1) of the MOCS3 protein, a bifunctional protein that also contains EC 2.7.7.80, molybdopterin-synthase adenylyltransferase, at the N-terminal domain.
the persulfide group that is exclusively formed on C412, the other three cyteine residues are not involved in sulfur transfer, mass spectrometric analysis, overview. A disulfide bridge between C316 and C324 is not essential for sulfur transfer in vitro
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 The sulfur is mobilized from L-cysteine by NFS1, a pyridoxal phosphate-dependent L-cysteine desulfurase, which forms a persulfide group on its conserved Cys-381 residue. The persulfide group is further transferred to Cys-412 of the C-terminal rhodanese-like domain of MOCS3
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 The sulfur is mobilized from L-cysteine by NFS1, a pyridoxal phosphate-dependent L-cysteine desulfurase, which forms a persulfide group on its conserved Cys-381 residue. The persulfide group is further transferred to Cys-412 of the C-terminal rhodanese-like domain of MOCS3
MOCS3 catalyzes both the adenylation and the subsequent generation of a thiocarboxylate group at the C-terminus of MOCS2A during Moco biosynthesis in humans. In humans and most eukaryotes thiosulfate is not the physiologic sulfur donor for MOCS3
MOCS3 catalyzes both the adenylation and the subsequent generation of a thiocarboxylate group at the C-terminus of MOCS2A during Moco biosynthesis in humans. In humans and most eukaryotes thiosulfate is not the physiologic sulfur donor for MOCS3
MOCS3 and the MOCS3 rhodanese-like domain, MOCS3-RLD, are also capable to catalyze the transfer of sulfur from thiosulfate to cyanide and shows dithiothreitol:thiosulfate oxidoreductase activity, kinetics, overview
MOCS3 and the MOCS3 rhodanese-like domain, MOCS3-RLD, are also capable to catalyze the transfer of sulfur from thiosulfate to cyanide and shows dithiothreitol:thiosulfate oxidoreductase activity, kinetics, overview
the MOCS3 rhodanese-like domain, MOCS3-RLD, is also capable to catalyze the transfer of sulfur from thiosulfate to cyanide and shows dithiothreitol:thiosulfate oxidoreductase activity, kinetics, overview
the MOCS3 rhodanese-like domain, MOCS3-RLD, is also capable to catalyze the transfer of sulfur from thiosulfate to cyanide and shows dithiothreitol:thiosulfate oxidoreductase activity, kinetics, overview
the MOCS3 rhodanese-like domain, MOCS3-RLD, is also capable to catalyze the transfer of sulfur from thiosulfate to cyanide. Recombinant MOCS3 can activate MOCS2A but not endogenous Escherichia coli MoaD. MOCS3 exhibits sulfurtransferase activity only with thiosulfate, clearly identifying the enzyme as thiosulfate sulfurtransferase. The thiosulfate sulfurtransferase activity of the separated MOCS3-RLD protein is comparable to that of intact MOCS3
the MOCS3 rhodanese-like domain, MOCS3-RLD, is also capable to catalyze the transfer of sulfur from thiosulfate to cyanide. Recombinant MOCS3 can activate MOCS2A but not endogenous Escherichia coli MoaD. MOCS3 exhibits sulfurtransferase activity only with thiosulfate, clearly identifying the enzyme as thiosulfate sulfurtransferase. The thiosulfate sulfurtransferase activity of the separated MOCS3-RLD protein is comparable to that of intact MOCS3
the two-domain protein MOCS3 catalyzes both the adenylation and the subsequent generation of a thiocarboxylate group at the C-terminus of MOCS2A by its C-terminal rhodanese-like domain (RLD), low activity ofMOCS3-RLD with thiosulfate as sulfur donor
the two-domain protein MOCS3 catalyzes both the adenylation and the subsequent generation of a thiocarboxylate group at the C-terminus of MOCS2A by its C-terminal rhodanese-like domain (RLD), low activity ofMOCS3-RLD with thiosulfate as sulfur donor
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 The sulfur is mobilized from L-cysteine by NFS1, a pyridoxal phosphate-dependent L-cysteine desulfurase, which forms a persulfide group on its conserved Cys-381 residue. The persulfide group is further transferred to Cys-412 of the C-terminal rhodanese-like domain of MOCS3
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 The sulfur is mobilized from L-cysteine by NFS1, a pyridoxal phosphate-dependent L-cysteine desulfurase, which forms a persulfide group on its conserved Cys-381 residue. The persulfide group is further transferred to Cys-412 of the C-terminal rhodanese-like domain of MOCS3
MOCS3 catalyzes both the adenylation and the subsequent generation of a thiocarboxylate group at the C-terminus of MOCS2A during Moco biosynthesis in humans. In humans and most eukaryotes thiosulfate is not the physiologic sulfur donor for MOCS3
MOCS3 catalyzes both the adenylation and the subsequent generation of a thiocarboxylate group at the C-terminus of MOCS2A during Moco biosynthesis in humans. In humans and most eukaryotes thiosulfate is not the physiologic sulfur donor for MOCS3
MOCS3 belongs to the class of rhodaneses that is found in combination with another protein domain, and contains one rhodanese domain of 158 amino acids at the C-terminus with a sequence identity of less than 20% with the classic two-domain rhodaneses, phylogenetic analysis of MoeB homologues, overview
the enzyme is involved in the biosynthesis of the molybdenum cofactor divided into three steps: conversion of GTP to precursor, transformation of the precursor to molybdopterin, and insertion of molybdenum into MPT to form the molybdenum cofactor
molybdopterin synthase sulfurase is involved in sulfur transfer to the C-terminus of the molybdopterin synthase, which synthesizes the molybdenum cofactor, that play a central role in several enzymes, role of specific conserved residues in the six amino acid active site loop of MOCS3-RLD in thiosulfate sulfurtransferase activity
the E1-catalyzed activation of the ubiquitin-like protein resembles the second step of the molybdenum cofactor (Moco) biosynthesis in humans and bacteria. For Moco biosynthesis in humans, the E1-like protein MOCS3 forms a thiocarboxylate group at the C-terminal glycine of the beta-grasp fold protein MOCS2A. molybdenum cofactor biosynthesis and tRNA thiolation steps are linked by the MOCS3 protein in humans, mechanism of protein conjugation and thiocarboxylate formation in sulfur transfer pathways, overview
the human MOCS3 gene encodes a protein involved in activation and sulfuration of the C-terminus of MOCS2A, the smaller subunit of the molybdopterin (MPT) synthase. MPT synthase catalyzes the formation of the dithiolene group of MPT that is required for the coordination of the molybdenum atom in the last step of molybdenum cofactor (Moco) biosynthesis. The L-cysteine desulfurase Nfs1 might be involved in the sulfuration ofMOCS3 in vivo. Sulfur transfer mechanism, overview
the human MOCS3 protein contains a C-terminal segment displaying similarities to the sulfurtransferase rhodanese. MOCS3 catalyzes both the adenylation and the subsequent generation of a thiocarboxylate group at the C-terminus of the smaller subunit of molybdopterin, MPT, synthase during molybdenum cofactor biosynthesis in humans. The N-terminus of MOCS3 is expected to activate the C-terminal glycine of, MOCS2A to form an acyl adenylate. Subsequently, the C-terminal rhodanese-like domain (RLD) of MOCS3 acts as a direct sulfur donor for the formation of a thiocarboxylate group on MOCS2A, The MOCS2A thiocarboxylate sulfur is used for the generation of the dithiolene moiety of molybdopterin which coordinates the molybdenum atom in molybdenum cofactor. The enzyme is able to provide the sulfur for the thiocarboxylation of MOCS2A in a defined in vitro system for the generation of MPT from precursor Z
the MOCS3 protein is believed to catalyze both the adenylation and the subsequent generation of a thiocarboxylate group at the C terminus of the smaller subunit of molybdopterin (MPT) synthase, the C-terminal segment of MOCS3 displays similarities to the sulfurtransferase rhodanese. The MOCS3 rhodanese-like domain provides the sulfur for the thiocarboxylation of MOCS2A, the small MPT synthase subunit in humans. C412 is important for catalysis. The MoeB domain of MOCS3 is not involved in sulfur transfer in vitro
MOCS3 interacts with both URM1, an ubiquitin-like modifier involved in the specific formation of 2-thiouridine tRNA in humans, and MOCS2A in vivo and in vitro, MOCS2A and URM1 are beta-grasp fold proteins that contain a highly conserved C-terminal double glycine motif. Deletion of the C-terminal glycine of either MOCS2A or URM1 results in a loss of interaction with MOCS3. Extension of the C-terminus with an additional glycine of MOCS2A and URM1 alters the localization of MOCS3from the cytosol to the nucleus
MOCS3 interacts with both URM1, an ubiquitin-like modifier involved in the specific formation of 2-thiouridine tRNA in humans, and MOCS2A in vivo and in vitro, MOCS2A and URM1 are beta-grasp fold proteins that contain a highly conserved C-terminal double glycine motif. Deletion of the C-terminal glycine of either MOCS2A or URM1 results in a loss of interaction with MOCS3. Extension of the C-terminus with an additional glycine of MOCS2A and URM1 alters the localization of MOCS3from the cytosol to the nucleus
Nfs1 interacts specifically with MOCS3-RLD and sulfur is transferred from L-cysteine to MOCS3-RLD via an Nfs1-bound persulfide intermediate. Cytosolic Nfs1 has an important role in sulfur transfer for the biosynthesis of Moco. Isd11 functions as an adapter and stabilizer of Nfs1. Sulfur transfer mechanism, overview
Nfs1 interacts specifically with MOCS3-RLD and sulfur is transferred from L-cysteine to MOCS3-RLD via an Nfs1-bound persulfide intermediate. Cytosolic Nfs1 has an important role in sulfur transfer for the biosynthesis of Moco. Isd11 functions as an adapter and stabilizer of Nfs1. Sulfur transfer mechanism, overview
the MOCS3 C-terminal domain is homologous to rhodanese-like proteins. The last amino acid must be either polar or positively charged to increase the thiosulfate sulfurtransferase activity of MOCS3-RLD
the MOCS3 C-terminal domain is homologous to rhodanese-like proteins. The last amino acid must be either polar or positively charged to increase the thiosulfate sulfurtransferase activity of MOCS3-RLD
the recombinant His6-tagged MOCS3-RLD is partially gluconoylated at the N-terminus which results in a heterogeneity of the protein but does not influence sulfurtransferase activity
the recombinant His6-tagged MOCS3-RLD is partially gluconoylated at the N-terminus which results in a heterogeneity of the protein but does not influence sulfurtransferase activity
site-directed mutagenesis, the kcat of the mutant variant is increased 83fold when dithiothreitol is used as reductant, or 470fold when cyanide is used as sulfur acceptor
site-directed mutagenesis, the mutant shows a 17fold increased dithiothreitol:thiosulfate oxidoreductase activity or a 90fold increased thiosulfate:cyanide sulfurtransferase activity
when the six amino acid active site loop of MOCS3 rhodanese-like domain is exchanged with the loop found in bovine rhodanese, thiosulfate:cyanide sulfurtransferase activity is increased 165fold. By site-directed mutagenesis also the whole loop is exchanged with the one found in bovine rhodanese, which results in a 36fold increase in the kcat with dithiothreitol in the assay mixture and a 165fold increased kcat with cyanide as sulfur acceptor
when the six amino acid active site loop of MOCS3 rhodanese-like domain is exchanged with the loop found in bovine rhodanese, thiosulfate:cyanide sulfurtransferase activity is increased 165fold. By site-directed mutagenesis also the whole loop is exchanged with the one found in bovine rhodanese, which results in a 36fold increase in the kcat with dithiothreitol in the assay mixture and a 165fold increased kcat with cyanide as sulfur acceptor
MOCS3 is encoded by an intronless gene located on chromosome 20, expression of wild-type and mutant tagged MOCS3 rhodanese-like domain, MOCS3-RLD, in Escherichia coli strain BL21(DE3)
Site-directed mutagenesis of the active site loop of the rhodanese-like domain of the human molybdopterin synthase sulfurase MOCS3. Major differences in substrate specificity between eukaryotic and bacterial homologs