Stearoyl Coenzyme A Desaturase 5 (SCD5)

Stearoyl-CoA desaturase (SCD) is an integral membrane protein of the endoplasmic reticulum that catalyzes the formation of monounsaturated fatty acids from saturated fatty acids. Four SCD isoforms, Scd1 through Scd4, have been identified in mouse. In contrast, only 2 SCD isoforms, SCD1 and SCD5, have been identified in human. SCD1 shares about 85% amino acid identity with all 4 mouse SCD isoforms, as well as with rat Scd1 and Scd2. In contrast, SCD5 shares limited homology with the rodent SCDs and appears to be unique to primates.The deduced 330-amino acid protein has a predicted molecular mass of 37.6 kD. Like other SCDs, SCD5 contains a unique N terminus followed by a 5-transmembrane region and 3 catalytic histidine boxes that are thought to bind nonheme iron required for enzymatic activity.