Mechanism of the feedback-inhibition resistance in aspartate kinase of Corynebacterium pekinense: from experiment to MD simulations

摘要: In microorganisms and plants, aspartate kinase (AK) is the initial committed enzyme of biosynthesis acid family amino acids inhibited by end products. paper, we mutated key allosteric regulatory site A380 around binding Lys inhibitor in Corynebacterium pekinense AK (CpAK). A single-mutant A380C was obtained with 12.35-fold higher activity through high-throughput screening. On this basis, T379 as another further modified, double-mutant T379N/A380C 22.79-fold obtained. Molecular dynamics (MD) simulations were used to investigate mechanism inhibition Lys. The results indicated that CpAK resulted conformational changes a larger distance between phosphorus atom ATP oxygen Asp, which detrimental for catalytic reaction. However, mutation sites opens “switch” regulation can prevent transformation. Some residues such G168, R203, D193 play an important role maintaining substrate enhance activity.