Protein Family Models

Sphingolipids are important membrane signalling molecules involved in many different cellular functions in eukaryotes. Sphingolipid delta 4-desaturase catalyses the formation of (E)-sphing-4-enine [1]. Some proteins in this family have bifunctional delta 4-desaturase/C-4-hydroxylase activity. Delta 4-desaturated sphingolipids may play a role in early signalling required for entry into meiotic and spermatid differentiation pathways during Drosophila spermatogenesis [1]. This small domain associates with FA_desaturase Pfam:PF00487 and appears to be specific to sphingolipid delta 4-desaturase. [1]. 11937514. Identification and characterization of a sphingolipid delta 4-desaturase family. Ternes P, Franke S, Zahringer U, Sperling P, Heinz E;. J Biol Chem 2002;277:25512-25518. (from Pfam)

Date:

2024-10-16

Fatty acid desaturases are enzymes that catalyse the insertion of a double bond at the delta position of fatty acids. There seem to be two distinct families of fatty acid desaturases which do not seem to be evolutionary related: Family 1 composed of Stearoyl-CoA desaturases (SCD) [1,2] and Family 2 composed of Bacterial fatty acid desaturases, Plant stearoyl-acyl-carrier-protein desaturase [3] and Cyanobacterial DesA [4]. Members of this entry are ER integral membrane proteins that share the same mushroom-shaped fold consisting of four transmembrane helices (TM1-TM4) which anchor them to the membrane, capped by a cytosolic domain containing a unique 9-10 histidine- coordinating di metal (di-iron) catalytic centre [5,6]. The structure of mouse stearoyl-CoA desaturase (SDC) revealed that TM2 and TM4 are longer than TM1 and TM3 and protrude into the cytosolic domain, providing three of the nine histidine residues that coordinate the two metal ions, while the other histidine residues are provided by the soluble domain in this enzyme [5]. [1]. 8861937. Crystal structure of delta9 stearoyl-acyl carrier protein desaturase from castor seed and its relationship to other di-iron proteins. Lindqvist Y, Huang W, Schneider G, Shanklin J;. EMBO J 1996;15:4081-4092. [2]. 2570068. Differentiation-induced gene expression in 3T3-L1 preadipocytes. A second differentially expressed gene encoding stearoyl-CoA desaturase. Kaestner KH, Ntambi JM, Kelly TJ Jr, Lane MD;. J Biol Chem. 1989;264:14755-14761. [3]. 2006187. Stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs. Shanklin . TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

sphingolipid delta(4)-desaturase family protein such as sphingolipid delta(4)-desaturase (also called dihydroceramide desaturase) which generates a trans double bond at position 4 of sphinganine bases in sphingolipids| fatty acid desaturase family protein may remove two hydrogen atoms from a fatty acid, creating a carbon/carbon double bond; such as Mycobacterium tuberculosis NADPH-dependent stearoyl-CoA 9-desaturase

Date:

2017-03-02