Submitted to: National Plant Lipid Cooperative Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/1995
Publication Date: N/A
Technical Abstract: Acetyl-CoA carboxylase (ACCase) catalyzes the ATP-dependent carboxylation of acetyl-CoA to form malonyl-CoA. In soybean we have characterized two > 14 kb nuclear-encoded ACCase genes (ACCase-A and B) and one 330 bp PCR amplified ACCase fragment from chloroplast DNA. ACCase-A is encoded by 6789 nucleotides in 31 exons. Compared to ACCase-A, the ACCase-B gene is missing g849 bp of coding sequence at its 3' end. Sequence data from neither gene has indicated the presence of a chloroplast transit peptide. The 330-bp PCR fragment shows > 85% sequence homology to the carboxybiotin binding domain of the accD gene which encodes a subunit of the prokaryotic-type ACCase. SDS-PAGE analysis of two ACCase fractions isolated from soybean embryos provides evidence for multiple forms of ACCase. One ACCase fraction contained a 210-220 kDa biotinylated polypeptide whereas the other ACCase fraction contained only lower molecular mass biotinylated polypeptides including a 35 kda band which may represent the BCCP subunit of the prokaryotic-type ACCase. We are using DNA probes to ACCase to determine its expression in soybean.