This is a default text for your page '. Click above on edit this page' to modify. Be careful with the < and > signs.
You may include any references to papers as in: the use of JSmol in Proteopedia [1] or to the article describing Jmol [2] to the rescue.
Function(s) and Biological Relevance
Lignostilbene-α,β-dioxygenase (LsdA) from the bacterium
'Sphingomonas paucimobilis'. It is a nonheme iron oxygenase that catalyzes the cleavage of lignostilbene, a compound
arising in lignin transformation, to two vanillin molecules. The substrate for this enzyme is lignostilbene. Phenylazophenol
inhibited the LsdA-catalyzed cleavage of lignostilbene in a
reversible, mixed fashion. Lignin is used in biofuel production. Lignin is a heterogeneous aromatic polymer found in plant
cell walls that contributes to the recalcitrance of biomass. Below are two images. On the left is Lignostilbene, and on the right is Vanillin for comparison.
Broader Implications
To examine LsdA’s substrate specificity, we heterologously produced the dimeric enzyme with the help of chaperones. When
tested on several substituted stilbenes, LsdA exhibited the greatest specificity for lignostilbene. These experiments further indicated that the substrate’s
4-hydroxy moiety is required for catalysis and that this moiety
cannot be replaced with a methoxy group. This expands our
mechanistic understanding of LsdA and related stilbene-cleaving dioxygenases.
Structural highlights and structure-function relationships
The is a fold of LsdA of a seven-bladed -propeller, typical of the CCOs.
.
The and space-filling view of the ligand in the protein, shows that both hydrophilic and hydrophobic residues are important to the ligand in the binding site.
Energy Transformation
Phenylazophenol inhibits the LsdA-catalyzed cleavage of lignostilbene in a reversible, mixed fashion.
