Entry M0106 126.96.36.199 pyruvate dehydrogenase (acetyl-transferring)
Glu59 deprotonates the thiamine diphosphate cofactor, which initiates double bond rearrangement that results in the deprotonation of the N=CH-S group, activating the cofactor.
Comment: Activation of the TPP (thiamine diphosphate) cofactor is by the formation of an ionic N1'-H...O bond between the N1' atom of the aminopyrimidine ring of the cofactor and the OG of the intrinsic Glu59, resulting in the transfer of a negative charge from the protein to the cofactor. This transfer then imposes an active V-conformation that brings the N4' atom of the cofactor to the distance required for the intramolecular C2-H...N4' hydrogen bond with the thiazolium C2 atom. This initial activation is then followed by abstraction of the proton from the C2 atom . In order to be analogous to the other thiamine diphosphate activation steps in MACiE, this activation is shown as a single step.
Amino acids involved in the reaction step.
Organic Cofactors involved in the reaction step
Metal Cofactors involved in Step 01
||Bonds Changed in Order
||Atom Types Involved
The C-C bond changes from a single to double bond
The C-N bond changes from a single to double bond
The C-C bond changes from a double to single bond
The C-N bond changes from a double to single bond
View similar reactions in MACiE.