EC Number   |
General Information |
Reference |
|---|
    1.14.14.5 | evolution |
the enzymes SfnG, MsuC, and MsuD are members of a small subset of flavin-dependent monooxygenases that are characterized by their use of reduced flavin as a cosubstrate rather than a cofactor. Termed two-component flavin-dependent monooxygenases, members of this family lack an NAD(P)H-binding site and therefore require a separate reduced NAD(P)H:oxidized flavin mononucleotide (FMN) oxidoreductase to provide the FMNH- cosubstrate |
-, 765077 |
| 1.14.14.5 | metabolism |
small- to medium-chain alkanesulfonate monooxygenase enzyme MsuD plays a role in the sulfur assimilation pathway. The flavin-dependent monooxygenases SfnG, MsuC, and MsuD convert DMSO2 to sulfite. SfnG converts DMSO2 to methanesulfinate (MSI-), MsuC oxidizes MSI- to methanesulfonate (MS-), and MsuD catalyzes the conversion of MS- to sulfite. Together SfnG and MsuD are responsible for sequential cleavage of the two C-S bonds of DMSO2, and each methyl group is presumed to be oxidized to formaldehyde |
-, 765077 |
| 1.14.14.5 | more |
molecular docking, structure-function analysis, roles of the active site lid, the protein C terminus, and an active site loop in flavin and/or alkanesulfonate binding, overview. These structures position MS- closest to the flavin N5 position, consistent with an N5-(hydro)peroxyflavin mechanism rather than a classical C4a-(hydro)peroxyflavin mechanism. A fully enclosed active site is observed in the ternary complex, mediated by interchain interaction of the C-terminus at the tetramer interface identifying a function of the protein C-terminus in this protein family in stabilizing tetramer formation and the alkanesulfonate-binding site. The structures of MsuD with and without ligands support ordered binding for FMNH- and MS-, and the preferential binding of FMN first within chains A/C and E/G is suggestive of possible cooperativity. Without ligands, the active site lid, the sulfonate-binding loop, and the protein C terminus are disordered |
-, 765077 |
| 1.14.14.5 | physiological function |
bacterial two-component flavin-dependent monooxygenases cleave the stable C-S bond of environmental and anthropogenic organosulfur compounds. The monooxygenase MsuD converts methanesulfonate (MS-) to sulfite, completing the sulfur assimilation process during sulfate starvation |
-, 765077 |
| 1.14.14.5 | physiological function |
genes SsuD and TauD, which encode an alkanesulfonate monooxygenase and a taurine dioxygenase, respectively, are both required to protect cells against oxidative stress, including that generated by n-hexadecane degradation and H2O2 exposure. Both the SsuD and TauD knockout strains exhibit increased sensitivity to H2O2 compared to the wild-type strain |
-, 763961 |
| 1.14.14.5 | physiological function |
optimal transfer of reduced flavin from NADPH-dependent FMN reductase SsuE to SsuD requires defined protein-protein interactions, but diffusion can occur under specified conditions. A SsuD variant containing substitutions of charged residues shows a 4fold decrease in coupled assays that include SsuE to provide reduced FMN, but there is no activity observed with an SsuD variant containing a deletion of the alpha-helix containing conserved charged amino acids |
744346 |
| 1.14.14.5 | physiological function |
salt bridges between Arg297 and Glu20 or Asp111 are not critical to the desulfonation mechanism. The predicted role of residue Arg297 is to favorably interact with the phosphate group of the reduced flavin. Arg226 functions as a protection group shielding FMNOO- from bulk solvent and is more pronounced when both FMNOO- and octanesulfonate are bound |
744319 |
