Data for Polyketide Synthase–Like Functionality Acquired by Plant Fatty Acid Elongase

Kim, H., Park, K., Jia, H., Huang, F., Tang, X., Zhong, T., Yu, W., Riethoven, J.M., Cahoon, R.E., Zhang, C., Cahoon, E.B. Nov. 9, 2026. “Data for Polyketide Synthase-like Functionality Acquired by Plant Fatty Acid Elongase.” University of Illinois Urbana-Champaign. DOI: 10.13012/B2IDB-5292111_V1.

Fatty acid elongation typically proceeds through a four-step cycle of condensation, reduction, dehydration, and reduction for each two-carbon extension. Here, we describe a variation of this pathway in Orychophragmus limprichtianus, whose seed oil contains previously unknown C24-C28 keto-hydroxy fatty acids that account for ~25% of total fatty acids. These compounds are produced through an endoplasmic reticulum–localized discontinuous elongation process in which a 3-keto-hydroxy intermediate bypasses full reduction and is extended through a polyketide synthase–like mechanism. Transcriptomic and functional assays identified two divergent enzymes, a variant fatty acid elongase 1 (FAE1) and a low-activity 3-ketoacyl-CoA reductase (KCR1), as central to this process. Protein modeling and mutant analysis suggest that specific amino acid substitutions underlie altered KCR1 activity, enabling accumulation of keto intermediates. Our findings reveal unexpected flexibility in plant fatty acid elongation and provide innovative tools for engineering plants and microbes to produce renewable oils with tailored industrial functions.

NCBI: Sinalliaria limprichtiana fatty acid elongase1/ketoacyl-CoA synthase 18 (FAE1-1) mRNA, complete cds

NCBI: Sinalliaria limprichtiana fatty acid elongase1/ketoacyl-CoA synthase 18 (FAE1-2) mRNA, complete cds

NCBI: Sinalliaria limprichtiana fatty acid elongase1/ketoacyl-CoA synthase 18 (FAE1-3) mRNA, complete cds

NCBI: Sinalliaria limprichtiana 3-ketoacyl-CoA reductase (KCR1-1) mRNA, complete cds

NCBI: Sinalliaria limprichtiana 3-ketoacyl-CoA reductase (KCR1-2) mRNA, complete cds

NCBI: PacBio transcriptome sequencing of Orychophragmus limprichtianus seeds

NCBI: TSA: Sinalliaria limprichtiana isolate SAMPLE_1_OL, transcriptome shotgun assembly

Illinois Data Bank: fatty acid compositions, growth complementation assay data