Reaction: stearoyl-[acyl-carrier protein] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = oleoyl-[acyl-carrier protein] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): stearyl acyl carrier protein desaturase; stearyl-ACP desaturase; acyl-[acyl-carrier-protein] desaturase; acyl-[acyl-carrier protein],hydrogen-donor:oxygen oxidoreductase
Systematic name: stearoyl-[acyl-carrier protein],reduced ferredoxin:oxygen oxidoreductase (9,10 cis-dehydrogenating)
Comments: The enzyme is found in the lumen of plastids, where de novo biosynthesis of fatty acids occurs, and acts on freshly synthesized saturated fatty acids that are still linked to acyl-carrier protein. The enzyme determines the position of the double bond by its distance from the carboxylic acid end of the fatty acid. It also acts on palmitoyl-[acyl-carrier-protein] [4,5].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37256-86-3
References:
1. Jaworski, J.G. and Stumpf, P.K. Fat metabolism in higher plants. Properties of a soluble stearyl-acyl carrier protein desaturase from maturing Carthamus tinctorius. Arch. Biochem. Biophys. 162 (1974) 158-165. [PMID: 4831331]
2. Nagai, J. and Bloch, K. Enzymatic desaturation of stearyl acyl carrier protein. J. Biol. Chem. 243 (1968) 4626-4633. [PMID: 4300868]
3. Shanklin, J. and Somerville, C. Stearoyl-acyl-carrier-protein desaturase from higher plants is structurally unrelated to the animal and fungal homologs. Proc. Natl. Acad. Sci. USA 88 (1991) 2510-2514. [PMID: 2006187]
4. Cahoon, E.B., Lindqvist, Y., Schneider, G. and Shanklin, J. Redesign of soluble fatty acid desaturases from plants for altered substrate specificity and double bond position. Proc. Natl. Acad. Sci. USA 94 (1997) 4872-4877. [PMID: 9144157]
5. Cao, Y., Xian, M., Yang, J., Xu, X., Liu, W. and Li, L. Heterologous expression of stearoyl-acyl carrier protein desaturase (S-ACP-DES) from Arabidopsis thaliana in Escherichia coli. Protein Expr. Purif. 69 (2010) 209-214. [PMID: 19716420]