MECR(Mitochondrial trans-2-enoyl-CoA reductase), also known as NRBF1, catalyzes the reduction of trans-2-enoyl-CoA to acyl-CoA with chain length from C6 to C16 in an NADPH dependent manner with preference to medium chain length substrate. This protein has a role in the mitochondrial synthesis of fatty acids. Recombinant human MECR protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.