MetaCyc Enzyme: sn-2 acyl-lipid 9-desaturase

Gene: desC2 Accession Number: G-14791 (MetaCyc)

Synonyms: sn-2 acyl-lipid Δ9 desaturase

Species: Nostoc sp. 36

Acyl-lipid desaturases desaturate carbon single bonds in fatty acids that are esterified to membrane-bound glycerolipids [Chintalapati06]. Four types of front-loading acyl-lipid desaturases, DesA, DesB, DesC and DesD, have been described in cyanobacteria, that act at the 12, 15, 9 and 6 positions, respectively.

While all of the enzymes initially described are specific for fatty acids bound to the sn-1 position of glycerolipids, this enzyme, characterized from the cyanobacterium Nostoc sp. 36, desaturates fatty acids esterified on the sn-2 position of glycerolipids [Chintalapati06].

The desC2 gene was cloned from Nostoc sp. 36 and expressed in the cyanobacterium Synechocystis sp. PCC 6803, which cannot desaturate fatty acids at the sn-2 position. Analysis of lipids from the recombinant host identifed a prominent increase in the level of palmitoleate at the sn-2 position, indicating that the enzyme indeed acts on fatty acids at that position [Chintalapati06].

Homologs of the desC2 gene were found in Nostoc sp. PCC 7120, Anabaena variabilis, Nostoc punctiforme, and Thermosynechococcus elongatus [Chintalapati06].

Molecular Weight of Polypeptide: 33.24 kD (from nucleotide sequence)

Unification Links: Entrez-Nucleotide:AJ621247 , UniProt:Q704E9

Relationship Links: InterPro:IN-FAMILY:IPR005804 , InterPro:IN-FAMILY:IPR015876 , Pfam:IN-FAMILY:PF00487 , Prints:IN-FAMILY:PR00075

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Created 28-Oct-2011 by Weerasinghe D , SRI International
Revised 06-Nov-2014 by Caspi R , SRI International

Enzymatic reaction of: sn-2 palmitoyl-lipid Δ9 desaturase (sn-2 acyl-lipid 9-desaturase)

a 1-acyl-2-palmitoyl-sn-glycerol 3-phosphate + 2 a reduced ferredoxin + oxygen + 2 H+ <=> a 1-acyl-2-palmitoleoyl-sn-glycerol 3-phosphate + 2 an oxidized ferredoxin + 2 H2O

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

The reaction is physiologically favored in the direction shown.

In Pathways: palmitoleate biosynthesis III (cyanobacteria)


Chintalapati06: Chintalapati S, Prakash JS, Gupta P, Ohtani S, Suzuki I, Sakamoto T, Murata N, Shivaji S (2006). "A novel Delta9 acyl-lipid desaturase, DesC2, from cyanobacteria acts on fatty acids esterified to the sn-2 position of glycerolipids." Biochem J 398(2);207-14. PMID: 16689682

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Tue Oct 13, 2015, BIOCYC11A.