ABSTRACT
Genes for subunits of acetyl coenzyme A carboxylase (ACC), which is the enzyme that catalyzes the first step in the synthesis of fatty acids in Lactobacillus plantarum L137, were cloned and characterized. We identified six potential open reading frames, namely,manB, fabH, accB, accC,accD, and accA, in that order. Nucleotide sequence analysis suggested that fabH encoded β-ketoacyl-acyl carrier protein synthase III, that theaccB, accC, accD, andaccA genes encoded biotin carboxyl carrier protein, biotin carboxylase, and the β and α subunits of carboxyltransferase, respectively, and that these genes were clustered. The organization ofacc genes was different from that reported forEscherichia coli, for Bacillus subtilis, and for Pseudomonas aeruginosa. E. coli accB andaccD mutations were complemented by the L. plantarum accB and accD genes, respectively. The predicted products of all five genes were confirmed by using the T7 expression system in E. coli. The gene product of accB was biotinylated in E. coli. Northern and primer extension analyses demonstrated that the five genes in L. plantarumwere regulated polycistronically in an acc operon.
Genes for two subunits of acetyl coenzyme A carboxylase of Anabaena sp. strain PCC 7120: biotin carboxylase and biotin carboxyl carrier protein.