Identification and characterization of the alpha-acetolactate synthase gene from Lactococcus lactis subsp. lactis biovar diacetylactis.
The conversion of 3-13C-labelled pyruvate in an acetoin-producing clone from a Lactococcus lactis subsp. lactis biovar diacetylactis strain DSM 20384 plasmid bank in Escherichia coli was studied by 13C nuclear magnetic resonance analysis. The results showed that alpha-acetolactate was the first metabolic product formed from pyruvate, whereas acetoin appeared at a much slower rate and reached only low concentrations. This alpha-acetolactate production shows that the cells express the gene for alpha-acetolactate synthase (als). Nucleotide sequence analysis identified an open reading frame encoding a protein of 554 amino acids. The deduced amino acid sequence exhibits extensive similarities to those of known alpha-acetolactate synthases from both prokaryotes and eukaryotes. The als gene is expressed on a monocistronic transcriptional unit, which is transcribed from a promoter located just upstream of the coding region.
Unilever Research Laboratorium, AT Vlaardingen, The Netherlands.
J D
JD
Marugg
D
D
Goelling
U
U
Stahl
A M
AM
Ledeboer
M Y
MY
Toonen
W M
WM
Verhue
C T
CT
Verrips
D000095:Acetolactate Synthase / Q000235:genetics / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification*; D001483:Base Sequence; D005798:Genes, Bacterial; D013294:Lactococcus lactis / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data
D001426:Bacterial Proteins; D000095:Acetolactate Synthase