Chorismate serves as a crucial precursor for the synthesis of many aromatic compounds essential for the survival and virulence in various bacteria and protozoans. Chorismate synthase, a vital enzyme in the shikimate pathway, is responsible for the formation of chorismate from enolpyruvylshikimate-3-phosphate (EPSP). Moraxella catarrhalis is reported to be resistant to many beta-lactam antibiotics and causes chronic ailments such as otitis media, sinusitis, laryngitis, and bronchopulmonary infections. Here, we have cloned the aroC gene from Moraxella catarrhalis in pET28c and heterologously produced the chorismate synthase (~ 43 kDa) in Escherichia coli BL21(DE3) cells. We have predicted the three-dimensional structure of this enzyme and used the refined model for ligand-based virtual screening against Supernatural Database using PyRx tool that led to the identification of the top three molecules (caffeic acid, gallic acid, and o-coumaric acid). The resultant protein–ligand complex structures were subjected to 50 ns molecular dynamics (MD) simulation using GROMACS. Further, the binding energy was calculated by MM/PBSA approach using the trajectory obtained from MD simulation. The binding affinities of these compounds were validated with ITC experiments, which suggest that gallic acid has the highest binding affinity amongst these three phytochemicals. Together, these results pave the way for the use of these phytochemicals as potential anti-bacterial compounds.

Chorismate是合成许多芳香化合物的关键前体，这些芳香化合物对于各种细菌和原生动物的生存和致病力至关重要。分支酸合酶是the草酸途径中的重要酶，负责由烯醇式丙酮酸shi草酸-3-磷酸酯（EPSP）形成分支酸。据报道，卡他莫拉菌对许多β-内酰胺抗生素具有抗药性，并引起慢性疾病，如中耳炎，鼻窦炎，喉炎和支气管肺部感染。在这里，我们从pET28c的卡他莫拉氏菌中克隆了aroC基因，并在大肠杆菌中异源地产生分支酸合酶（〜43 kDa）。BL21（DE3）细胞。我们已经预测了这种酶的三维结构，并使用精细的模型对超自然数据库进行了基于PyRx工具的基于虚拟配体的虚拟筛选，从而鉴定出了前三个分子（咖啡酸，没食子酸和邻香豆酸） ）。使用GROMACS对所得的蛋白质-配体复合物结构进行了50 ns的分子动力学（MD）模拟。此外，使用从MD模拟获得的轨迹通过MM / PBSA方法计算结合能。这些化合物的结合亲和力已通过ITC实验验证，这表明没食子酸在这三种植物化学物质中具有最高的结合亲和力。总之，这些结果为将这些植物化学物质用作潜在的抗菌化合物铺平了道路。