The acyl-CoA synthetase medium-chain (ACSM) family is comprised of ACSM1, ACSM2A, ACSM2B, ACSM3, ACSM4 and ACSM5, which encode for enzymes catalyzing the activation of medium-chain length fatty acids. ACSM5 is a 579 amino acid protein has a broad substrate specificity and utilizes magnesium or manganese as a cofactor.