User:Jordan Finch/Sandbox 1
From Proteopedia
TextToBeDisplayed</scene>
Histone Acetyltransferase HAT1/HAT2 Complex, Saccharomyces cerevisiaeThis is a default text for your page Caitlin Marie Gaich/Sandbox1. 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. IntroductionHAT1 Background Hat1/Hat2 Complex StructureThis 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. MechanismOf the five classes of HAT enzymes, the catalytic mechanisms for two of those enzymes, HAT1 and Rtt109, remains unclear. A structural overlay of HAT1 and Gcn5, a more well-known and understood HAT enzyme, found a conserved glutamate residue in the active site of both molecules. It was found that mutation at that active site glutamate residue greatly alters the catalytic ability of HAT1 and has been proven to be structurally important. [3] Using this information and structural information regarding the proximity of potentially catalytic residues, the most plausible mechanism for histone acetylation involves the following relevant residues and cofactors . In this mechanism, the glutamate at residue 255 acts as a general base and deprotonates lysine 12 of histone 4 (the numbering of the modified lysine residue on histone 4 is shifted two residues).The deprotonated lysine then acts as a nucleophile and attacks the carbonyl carbon of acetyl coenzyme A (CoA, forming a tetrahedral intermediate transition state. The negative charge on the oxygen collapses down to for a double bond and the scissle bond between the carbonyl carbon and the sulfur atom of acetyl CoA is broken. The resulting product of this reaction is histone 4 with an acetyl-lysine at residue 12 and CoEnzyme A. ApplicationReferences
Student Contributors
| ||||||||||||
