Thioesterase Superfamily, Member 5 (THEM5)

Them5 encodes a protein with acyl-CoA thioesterase activity towards medium (C12) and long-chain (C18) fatty acyl-CoA substrates. Expression of a similar murine protein in brown adipose tissue is induced by cold exposure and repressed by warmth. Expression of the mouse protein has been associated with obesity, with higher expression found in obesity-resistant mice compared with obesity-prone mice. Alternative splicing results in two transcript variants encoding different isoforms. Acyl-CoA thioesterases are a group of enzymes catalyzing the hydrolysis of acyl-CoAs to fatty acids and unesterified CoA (CoASH).3 Two types of acyl-CoA thioesterases have been found in Escherichia coli. The acyl-CoA thioesterase II (TesB) of E. coli is a tetramer with a molecular mass of 120 kDa and cleaves C6-C18 acyl-CoA esters as well as 3-hydroxyacyl-CoA esters.