EC Number   |
General Information |
Reference |
|---|
    2.7.7.80 | evolution |
MoeB beongs to the MoeB/E1 enzyme superfamily, conserved active site structure, overview. The molybdenum cofactor (Moco) biosynthesis, involving Escherichia coli proteins MoeB and MoaD, is an evolutionarily conserved pathway |
723259 |
| 2.7.7.80 | malfunction |
in homozygous MOCS3-knockout HEK293T cells, sulfite oxidase activity is almost completely abolished, on the basis of the absence of Moco in these cells. In addition, mcm5s2U thio-modified tRNAs are not detectable. Impact of a MOCS3 knockout on the cellular localization of NFS1, MOCS3-independent localization of NFS1 (a L-cysteine desulfurase NFS1 acting as a sulfur donor for MOCS3 in the cytosol) at the tips of the centrosome |
760600 |
| 2.7.7.80 | malfunction |
The Escherichia coli moeB mutant strains contain an inactive, desulfo form of MPT synthase. Substitutions of every cysteine residue in MoeB does not affect activity, except for the mutations in the cysteine residues located in putative Zn-binding motifs, which cause loss of metal binding correlated with loss of activity |
722621 |
| 2.7.7.80 | metabolism |
Escherichia coli proteins MoeB and MoaD are involved in molybdenum cofactor (Moco) biosynthesis |
723259 |
| 2.7.7.80 | more |
the human MOCS3 protein contains an N-terminal domain similar to the Escherichia coli MoeB protein. This N-terminal MoeB-like domain is active in catalyzing the adenylyltransferase activity, and C239 of the N-terminal MoeB-like domain of MOCS3 is most likely involved in the sulfur transfer mechanism of the persulfide sulfur to MOCS2A |
721600 |
| 2.7.7.80 | physiological function |
human MOCS3 is a dual-function protein that plays an important role in Moco biosynthesis and in the mcm5s2U thio modifications of nucleosides in cytosolic tRNAs for Lys, Gln, and Glu. Cellular roles of MOCS3, overview. MOCS3 is involved in mcm5s2U34 tRNA modifications in the cytosol by forming a thiocarboxylate group on URM1, which is further used as sulfur-providing protein for the tRNA nucleoside modification. The overall cytosolic levels of the mcm5s2U modification seem to be very low |
760600 |
| 2.7.7.80 | physiological function |
MOCS3 catalyzes both the adenylation and the subsequent generation of a thiocarboxylate group at the C-terminus of the smaller subunit of molybdopterin synthase during molybdenum cofactor biosynthesis in humans. Similar to ubiquitin activating enzymes, 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 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 the molybdenum cofactor |
721600 |
| 2.7.7.80 | physiological function |
MoeB is involved in molybdenum cofactor (Moco) biosynthesis, it activates the C-terminus of MoaD to form an acyl-adenylate. The MoeB-MoaD interface is the C-terminal extension of the MoaD C-terminus into a pocket on the MoeB surface, MoeB-MoaD-ATP ternary complex structure, overview. A preference for small amino acids (Gly, Ala, Ser) at the centre of beta5 of MoeB, facilitating the insertion of the Gly-Gly motif of MoaD into the active site of MoeB, Arg 14 is inserted into the active site across the dimer interface and has a critical role during ATP hydrolysis |
723259 |
| 2.7.7.80 | physiological function |
MoeB is involved in the activation of molybdopterin synthase for the biosynthesis of the molybdenum cofactor. MoeB-dependent formation of a C-terminal thiocarboxylate on the MoaD subunit of molybdopterin synthase might resemble the ubiquitin-activating step in the ubiquitin-targeted degradation of proteins in eukaryotes, but without formation of a thioester intermediate between MoeB and MoaD, overview. But formation of a complex of MoeB and MoaD adenylate, that is stable to gel filtration, occurs |
722621 |
| 2.7.7.80 | physiological function |
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 N-terminal MOCS3 MoeB-like domain, i.e. MOCS3-MoeBD, is similar to the Escherichia coli MoeB protein |
723621 |
