Molecular characterization of Lactobacillus plantarum genes for beta-ketoacyl-acyl carrier protein synthase III (fabH) and acetyl coenzyme A carboxylase (accBCDA), which are essential for fatty acid biosynthesis
P. Kiatpapan et al., Molecular characterization of Lactobacillus plantarum genes for beta-ketoacyl-acyl carrier protein synthase III (fabH) and acetyl coenzyme A carboxylase (accBCDA), which are essential for fatty acid biosynthesis, APPL ENVIR, 67(1), 2001, pp. 426-433
Genes for subunits of acetyl coenzyme A carboxylase (ACC), which is the enz
yme that catalyzes the first step in the synthesis of fatty acids in Lactob
acillus plantarum L137, were cloned and characterized. We identified six po
tential open reading frames, namely, manB, fabH, accB, accC, accD, and accA
, in that order. Nucleotide sequence analysis suggested that fabH encoded b
eta -ketoacyl-acyl carrier protein synthase III, that the accB, accC, accD,
and accA genes encoded biotin carboxyl carrier protein, biotin carboxylase
, and the beta and alpha subunits of carboxyltransferase, respectively, and
that these genes were clustered. The organization of acc genes was differe
nt from that reported for Escherichia coli, for Bacillus subtilis, and for
Pseudomonas aeruginosa. E. coli accB and accD mutations were complemented b
y the L. plantarum accB and accD genes, respectively. The predicted product
s 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 pr
imer extension analyses demonstrated that the five genes in L. plantarum we
re regulated polycistronically in an acc operon.