EC Number   |
General Information |
Reference |
|---|
  1.5.1.38 | evolution |
enzyme SsuE is part of the flavodoxin-like superfamily. A Pi-helix present at the tetramer building interface of enzyme Ssue is unique to the reductases from two-component monooxygenase systems |
741896 |
| 1.5.1.38 | evolution |
the flavin reductase of the alkanesulfonate monooxygenase system (SsuE) contains a conserved Pi-helix located at the tetramer interface that originates from the insertion of Tyr118 into helix alpha4 of SsuE, the presence of Pi-helices provides an evolutionary gain of function. Residue Tyr118 residue generates the Pi-helix in SsuE |
741937 |
| 1.5.1.38 | evolution |
the SsuE FMN reductase of the alkanesulfonate monooxygenase system belongs to the NAD(P)H:FMN reductase family based on a conserved flavodoxin fold. The subgroup of enzymes in the NAD(P)H:FMN reductase family is comprised of flavin reductases from two-component monooxygenase systems. The diverging structural feature in these FMN reductases is a Pi-helix centrally located at the tetramer interface that is generated by the insertion of an amino acid in a conserved alpha4 helix |
764152 |
| 1.5.1.38 | malfunction |
the Tyr insertional residue of SsuE makes specific contacts across the dimer interface that may assist in the altered mechanistic properties of this enzyme. The Y118F SsuE variant maintains the Pi-Pi stacking interactions at the tetramer interface and has kinetic parameters similar to those of wild-type SsuE. Substitution of the Pi-helical residue (Tyr118) to Ala or Ser transforms the enzymes into flavin-bound SsuE variants that can no longer support flavin reductase and desulfonation activities. These variants exist as dimers and can form protein-protein interactions with SsuD even though flavin transfer is not sustained. The DELRAY118 SsuE variant is flavin-free as purified and does not undergo the tetramer to dimer oligomeric shift with the addition of flavin. The absence of desulfonation activity can be attributed to the inability of DELTAY118 SsuE to promote flavin transfer and undergo the requisite oligomeric changes to support desulfonation. Results from these studies provide insights into the role of the SsuE Pi-helix in promoting flavin transfer and oligomeric changes that support protein-protein interactions with SsuD |
764152 |
| 1.5.1.38 | metabolism |
a general catalytic cycle is proposed for two-component reductases of the flavodoxin-like superfamily, by which the enzyme can potentially provide FMNH2 to its partner monooxygenase by different routes depending on the FMN concentration and the presence of a partner monooxygenase SsueD, overview |
741896 |
| 1.5.1.38 | more |
at least a dimeric association is required for the function of enzyme SsuE, FMN binding site structure, overview |
741896 |
| 1.5.1.38 | more |
enzyme structure analysis, structure-function relationship and substrate binding, overview |
764152 |
| 1.5.1.38 | physiological function |
FMN reductase (SsuE) catalyzes the reduction of FMN by NADPH, and the reduced flavin is transferred to the monooxygenase (SsuD) |
672426 |
| 1.5.1.38 | physiological function |
NADPH:FMN oxidoreductase is involved in bioluminescence by providing reduced FMN to luciferase |
392299 |
| 1.5.1.38 | physiological function |
SsuD is a monooxygenase that catalyzes the desulfonation of alkanesulfonates and requires reduced FMN, which is provided by the NAD(P)H:flavin oxidoreductase SsuE |
438770 |
