We used a PCR-based method to generate a single base pair mutation in the proB gene of Streptococcus thermophilus, which replaced an aspartic acid with a glycine residue at position 192 of the first proline biosynthetic enzyme γ-glutamyl kinase. This was the first identified mutation in amino acid biosynthesis in S. thermophilus to our knowledge. The mutation caused an enhanced, feedback-resistant γ-glutamyl kinase activity and conferred an analogue-resistant phenotype to an Escherichia coli transformant containing the mutated gene. Copyright (C) 2000.
Massarelli, I., Forlani, G., Ricca, E., & De Felice, M. (2000). Enhanced and feedback-resistant γ-glutamyl kinase activity of an Escherichia coli transformant carrying a mutated proB gene of Streptococcus thermophilus. FEMS Microbiology Letters, 182(1), 143–147. https://doi.org/10.1016/S0378-1097(99)00573-X