초록
<P><SMALL>L</SMALL>-Histidine is an essential proteinogenic amino acid in food with extensive applications in the pharmaceutical field. Herein, we constructed a <I>Corynebacterium glutamicum</I> recombinant strain for efficient biosynthesis of <SMALL>L</SMALL>-histidine. First, to alleviate the <SMALL>L</SMALL>-histidine feedback inhibition, the ATP phosphoribosyltransferase mutant HisG<SUB>T235P-Y56M</SUB> was constructed based on molecular docking and high-throughput screening, resulting in the accumulation of 0.83 g/L of <SMALL>L</SMALL>-histidine. Next, we overexpressed rate-limiting enzymes including HisG<SUB>T235P-Y56M</SUB> and PRPP synthetase and knocked out the <I>pgi</I> gene in the competing pathway, which increased the <SMALL>L</SMALL>-histidine production to 1.21 g/L. Furthermore, the energy status was optimized by decreasing the reactive oxygen species level and enhancing the supply of adenosine triphosphate, reaching a titer of 3.10 g/L in a shake flask. The final recombinant strain produced 5.07 g/L of <SMALL>L</SMALL>-histidine in a 3 L bioreactor, without the addition of antibiotics and chemical inducers. Overall, this study developed an efficient cell factory for <SMALL>L</SMALL>-histidine biosynthesis by combinatorial protein engineering and metabolic engineering.</P><BR>[FIG OMISSION]</BR>