Identification and characterization of the alpha-acetolactate synthase gene from Lactococcus lactis subsp. lactis biovar diacetylactis

• Published in: Applied and Environmental Microbiology Vol. 60; no. 4; pp. 1390 - 1394
• Main Authors: MARUGG, J. D, GOELLING, D, STAHL, U, LEDEBOER, A. M, TOONEN, M. Y, VERHUE, W. M, VERRIPS, C. T
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.04.1994
• Subjects: Acetolactate Synthase - genetics; Acetolactate Synthase - isolation & purification; Amino Acid Sequence; Bacterial Proteins - genetics; Bacterial Proteins - isolation & purification; Bacteriology; Base Sequence; Biological and medical sciences; expresion genica; expression des genes; Fundamental and applied biological sciences. Psychology; gene; gene expression; genes; Genes, Bacterial; Genes. Genome; Genetics; lactococcus lactis; Lactococcus lactis - enzymology; Lactococcus lactis - genetics; Lactococcus lactis lactis; liasas; lyase; lyases; Microbiology; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; nucleotide sequence; secuencia nucleica; sequence nucleique; Nucleotide sequence; Enzyme; Sequence alignment; Pyruvate; Homology; Gene organization; Lyases; Gene expression; Metabolism; Oxo-acid-lyases; Streptococcaceae; Carbon-carbon lyases; Lactococcus lactis subsp. lactis; Acetolactate synthase; Bacteria; Micrococcales; Comparative study; Aminoacid sequence
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.60.4.1390-1394.1994

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.