The crystal structure of human mitochondrial 3-ketoacyl-CoA thiolase (T1): insight into the reaction mechanism of its thiolase and thioesterase activities

Structural and enzymological characterization of the human degradative medium-chain-specific 3-ketoacyl-CoA thiolase (hT1) shows that its structure is highly similar to the short-chain-specific tetrameric biosynthetic thiolases, except for small structural differences in two loops at the active site, which provide extra space for a medium-chain fatty-acyl tail to bind. The intrinsic thioesterase activity of hT1 is also discussed.