Protein Family Models

This entry includes fatty acid and carotene hydroxylases and sterol desaturases. Beta-carotene hydroxylase is involved in zeaxanthin synthesis by hydroxylating beta-carotene, but the enzyme may be involved in other pathways [1]. This family includes C-5 sterol desaturase and C-4 sterol methyl oxidase [2,3,6]. Members of this family are involved in cholesterol biosynthesis and biosynthesis a plant cuticular wax [4]. These enzymes contain two copies of a HXHH motif which coordinate two irons at the catalytic centre. Members of this family are ER integral membrane proteins that share a novel mushroom-shaped fold consisting of four transmembrane (TM1-TM4) helices that anchor them to the membrane capped by a cytosolic domain containing the unique histidine- coordinating di metal centre [5]. [1]. 9353282. Fah1p, a Saccharomyces cerevisiae cytochrome b5 fusion protein, and its Arabidopsis thaliana homolog that lacks the cytochrome b5 domain both function in the alpha-hydroxylation of sphingolipid-associated very long chain fatty acids. Mitchell AG, Martin CE;. J Biol Chem 1997;272:28281-28288. [1]. 10431816. The zeaxanthin biosynthesis enzyme beta-carotene hydroxylase is involved in myxoxanthophyll synthesis in Synechocystis sp. PCC 6803. Lagarde D, Vermaas W;. FEBS Lett 1999;454:247-251. [2]. 1864507. Cloning, disruption and sequence of the gene encoding yeast C-5 sterol desaturase. Arthington BA, Bennett LG, Skatrud PL, Guynn CJ, Barbuch RJ, Ulbright CE, Bard M;. Gene 1991;102:39-44. [3]. 8552601. Cloning and characterization of ERG25, the Saccharomyces cerevisiae gene encoding C-4 sterol methyl oxidase. Bard M, Bruner DA, Pier. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

sterol desaturase family protein is an oxidoreductase belonging to the fatty acid hydroxylase superfamily, similar to C-5 sterol desaturase, which catalyzes a dehydrogenation reaction to introduce a C5-6 double bond into substrates such as lathosterol and the B ring of ergosterol

Date:

2024-07-11