Molecular Characterization of Multi-Functional Acetyl Coenzyme A Carboxylase, Biotin Carboxylase and beta-Carboxyltransferase from Arachis hypogaea L.

Acetyl-CoA carboxylase (ACCase; EC 6.4.1.2) catalyzes the synthesis of malonyl-CoA, the first intermediate in fatty acid synthesis. Genes for multi-functional acetyl-CoA carboxylase and two subunits of multi-subunit acetyl-CoA carboxylase, biotin carboxylase and β-Carboxyltransferase, have been cloned from peanut. The ORF of the three proteins are 6783bp, 1623bp, 1479 bp in length, encoding 2260, 540, 492 amino acids, respectively. The predicted amino acid sequences of the multi-functional AhACCase and AhBC from peanut shared high sequence identity, 90.9% and 88%, to the corresponding Glycine max proteins, respectively, while the amino acid sequence of AhβCT gene showed 71.6% identity with that from Nothofagus gunnii. Phylogenetic analysis showed that all of these three genes from peanut were grouped into the big branch of proteins from higher plant. Moreover, observation of the tree revealed that multi-functional ACCase genes may arise by independent gene duplication events in green algae and higher plants branches, and the biotin carboxylase and β-Carboxyltransferase genes from cyanobacteria may be the origin of genes from higher plants, mosses and eukaryotic algae.