Engineering and finetuning expression of SerC for balanced metabolic flux in vitamin B6 production

Abstract

Vitamin B₆ plays a crucial role in cellular metabolism and stress response, making it an essential component for growth in all known organisms. However, achieving efficient biosynthesis of vitamin B₆ faces the challenge of maintaining a balanced distribution of metabolic flux between growth and production. In this study, our focus is on addressing this challenge through the engineering of phosphoserine aminotransferase (SerC) to resolve its redundancy and promiscuity. The enzyme SerC was semi-designed and screened based on sequences and predicted k_cat values, respectively. Mutants and heterologous proteins showing potential were then fine-tuned to optimize the production of vitamin B₆. The resulting strain enhances the production of vitamin B₆, indicating that different fluxes are distributed to the biosynthesis pathway of serine and vitamin B₆. This study presents a promising strategy to address the challenge posed by multifunctional enzymes, with significant implications for enhancing biochemical production through engineering processes.

Keywords: Metabolic flux distribution; Multifunctional enzymes; Phosphoserine aminotransferase SerC; Protein engineering; Vitamin B6.