A Poly-γ-glutamate Synthetic System of Bacillus subtilis IFO 3336: Gene Cloning and Biochemical Analysis of Poly-γ-glutamate Produced by Escherichia coli Clone Cells

• Published in: Biochemical and biophysical research communications Vol. 263; no. 1; pp. 6 - 12
• Main Authors: Ashiuchi, Makoto, Soda, Kenji, Misono, Haruo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 16-09-1999
• Subjects: Amino Acid Isomerases - genetics; Amino Acid Sequence; Bacillus anthracis; Bacillus natto; Bacillus subtilis; Bacillus subtilis - genetics; Bacillus subtilis - metabolism; Base Sequence; Cloning, Molecular; DNA Primers - genetics; DNA, Bacterial - genetics; Escherichia coli; Escherichia coli - genetics; Escherichia coli - metabolism; Gene Expression; Genes, Bacterial; Magnesium - pharmacology; Manganese - pharmacology; Molecular Sequence Data; Plasmids - genetics; Polyglutamic Acid - biosynthesis; Polyglutamic Acid - chemistry; Species Specificity; Stereoisomerism
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1999.1298

Three genes encoding a poly-γ-glutamate synthetic system of Bacillus subtilis IFO 3336 (Bacillus natto) were cloned and expressed in Escherichia coli. The E. coli clone produced poly-γ-glutamate extracellularly. The genes, newly designated as pgsBCA, were homologous with capBCA genes of Bacillus anthracis. All of pgsB, pgsC, and pgsA genes were essential for the polymer production. Addition of Mn2+, instead of Mg2+, to the polymer-synthesis medium resulted in an increase in the polymer yield. Co-expression of glutamate racemase gene in E. coli cells harboring pgsBCA genes increased both the polymer production and d-glutamate content in the polymer. The polymer produced by the E. coli clone was higher in average molecular size than that produced by B. subtilis IFO 3336.