Fatty acid desaturases (FADS) are enzymes that convert a single bond between two carbon atoms (C–C) to a double bond (C=C) in a fatty acyl chain.
The resultant double bond is often referred to as an unsaturated bond, and the reactions catalyzed by these enzymes are knownas desaturation reactions.
These reactions require molecular oxygen and occur under aerobic conditions.
The distribution of fatty acid desaturases is almost universal.
The enzyme has been found in all organisms examined, with the exception of some bacteria such as Escherichiacoli.
There are three types of fatty acid desaturase: FADS1, FADS2 and FADS3.
FADS1 encodes a deduced 444-amino acid protein that shares a high degree of homology with FADS2 and FADS3.