Isolation and characterization of a cDNA fromCuphea lanceolata encoding a β-ketoacyl-ACP reductase
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- Klein, B., Pawlowski, K., Höricke-Grandpierre, C. et al. Molec. Gen. Genet. (1992) 233: 122. doi:10.1007/BF00587569
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A cDNA encoding β-ketoacyl-ACP reductase (EC 18.104.22.168), an integral part of the fatty acid synthase type II, was cloned fromCuphea lanceolata. This cDNA of 1276 by codes for a polypeptide of 320 amino acids with 63 N-terminal residues presumably representing a transit peptide and 257 residues corresponding to the mature protein of 27 kDa. The encoded protein shows strong homology with the amino-terminal sequence and two tryptic peptides from avocado mesocarp β-ketoacyl-ACP reductase, and its total amino acid composition is highly similar to those of the β-ketoacyl-ACP reductases of avocado and spinach. Amino acid sequence homologies to polyketide synthase, β-ketoreductases and short-chain alcohol dehydrogenases are discussed. An engineered fusion protein lacking most of the transit peptide, which was produced inEscherichia coli, was isolated and proved to possess β-ketoacyl-ACP reductase activity. Hybridization studies revealed that inC. lanceolata β-ketoacyl-ACP reductase is encoded by a small family of at least two genes and that members of this family are expressed in roots, leaves, flowers and seeds.