 It contains an element in the C-terminal region referred to as a "gatekeeper" helix, which is adjacent to the membrane-anchored transmembrane domain and the catalytic core.The gatekeeper helix appears to control access of molecular substrates to the catalytic core and allows efficient transit between membranes and catalytic sites.ALDH3A2 catalyzes the oxidation of long-chain aliphatic aldehydes into fatty acids.