The AROM complex is a multifunctional metabolic machine with ten enzymatic domains catalyzing the five central steps of the shikimate pathway in fungi and protists. We determined its crystal structure and catalytic behavior, and elucidated its conformational space using a combination of experimental and computational approaches. We derived this space in an elementary approach, exploiting an abundance of conformational information from its monofunctional homologs in the Protein Data Bank. It demonstrates how AROM is optimized for spatial compactness while allowing for unrestricted conformational transitions and a decoupled functioning of its individual enzymatic entities. With this architecture, AROM poses a tractable test case for the effects of active site proximity on the efficiency of both natural metabolic systems and biotechnological pathway optimization approaches. We show that a mere colocalization of enzymes is not sufficient to yield a detectable improvement of metabolic throughput.

AROM 复合物是一种多功能代谢机器，具有十个酶域，可催化真菌和原生生物中莽草酸途径的五个中心步骤。我们确定了它的晶体结构和催化行为，并结合实验和计算方法阐明了它的构象空间。我们以基本方法推导出这个空间，利用蛋白质数据库中其单功能同系物的丰富构象信息。它展示了 AROM 如何针对空间紧凑性进行优化，同时允许不受限制的构象转变和其各个酶实体的解耦功能。有了这个架构，AROM 为活性位点接近对自然代谢系统和生物技术途径优化方法效率的影响提出了一个易于处理的测试案例。我们表明，仅仅酶的共定位不足以产生可检测的代谢通量改善。