Part:BBa_K4989000

Acetyl-CoA C-acetyltransferase (thl)

The thl gene codes for an enzyme named acetyl-CoA C-acetyltransferase which belongs to the family of thiolases. This is the key enzyme for the condensation of two molecules of acetyl-CoA, which are produced from the glycolysis path, and the acetoacetyl-CoA production [3]. This is a reaction that thermodynamically itself is not favored. It starts with the acylation of a nucleophilic cysteine at the active site by acetyl-CoA (or a different acyl group) with the release of the CoA group. Then the acyl group is transferred to an acetyl-CoA molecule.

The chemical reactions that take place are shown below:
(1) acyl-CoA + acetyl-CoA = CoA + 3-oxoacyl-CoA
(1a) acetyl-CoA C-acyltransferase-S-acyl-L-cyteine + acetyl-CoA = 3-oxoacyl-CoA + acetyl-CoA C-acyltransferase-L-cyteine
(1b) acyl-CoA + acetyl-CoA C-acyltransferase-L-cyteine = acetyl-CoA C-acyltransferase-S-acyl-L-cyteine + CoA