This is a default text for your page Sandbox Wabash 06 Fumarase. 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.
Debate
Two mutant forms of fumarase C from E. coli have been made using PCR and recombinant DNA. Two different carboxylic acid binding sites (A+B) were observed in the crystal structures of the WT inhibited forms of the enzyme.
Crystallographic studies with several inhibitors including pyromellitic acid and B-trimethylsilyl maleate yielded interesting results. While both inhibitors are related to the normal substrate, each was found bound at different sites. The binding site of inhibitors citrate and pyromellitic acid was deemed the A site while a second site containing L-malate and B-trimethylsilyl maleate was labeled as the B-site. The first argument for site A being the active site was that the A site was formed by 3 of the 4 subunits. Secondly, citrate was used at high concentrations as a crystallizing agent and is known to competitively inhibit fumarase. As such, in X-ray studies, citrate was not able to be removed readily from the specimen preparation and it pointed to the A site. In regards to the B site, it was first noted that atoms of a single subunit formed the B site. Strong arguments were then made against the B site as no active monomeric form of fumarase has ever been described.
True Active Site
Structural highlights
This is a sample scene created with SAT to by Group, and another to make of the protein. You can make your own scenes on SAT starting from scratch or loading and editing one of these sample scenes.
