MECR

Trans-2-enoyl-CoA reductase, mitochondrial is an enzyme that in humans is encoded by the MECR gene.

Structure

The MECR gene is located on the 1st chromosome, with its specific location being 1p35.3. The gene contains 15 exons. MECR encodes a 21.2 kDa protein that is composed of 189 amino acids; 10 peptides have been observed through mass spectrometry data.

The protein encoded by MECR is an oxidoreductase that catalyzes the last step in mitochondrial fatty acid synthesis. MECR reduces trans-2-enoyl-ACP to acyl-ACP using NADPH as a reducing agent. The resulting saturated acyl-ACP can then re-enter the mtFAS cycle for further chain elongation. The reaction can be summarized by the following equation:
trans-2-enoyl-ACP + NADPH + H⁺ → Acyl-ACP + NADP⁺
The mtFAS pathway is essential for producing octanoyl-ACP that is used to synthesize lipoic acid, which is essential for aerobic metabolism.
A Purkinje cell specific knock out of the Mecr gene in mice leads to neurodegeneration.

Genetic mutations to MECR have been suggested to cause MEPAN Syndrome, a neurometabolic disorder in humans that involves disruptions in the pathway involved in mitochondrial fatty acid synthesis. MEPAN patients were found to harbor recessive mutations in MECR, and typically present with childhood-onset dystonia, optic atrophy, and basal ganglia signal abnormalities on MRI.