Heme-sensing ChrS/ChrA system from Corynebacterium diphtheriae

为了在宿主体内感染和繁殖，病原菌优先使用铁获取系统从宿主Hb获得铁。白喉棒状杆菌是白喉的病原体，通过铁/血红素调节CHRS/Chra系统。在本研究中，CHRS蛋白从一株高产大肠杆菌的膜上溶解和纯化，然后被结合到纳米盘中。重组的CHRS蛋白通过其第一跨膜区的His21直接和特异地识别血红素，依赖于血液的自磷酸化和向Chra的磷酸化转移。

To infect and proliferate in the host, pathogenic bacteria preferentially acquire iron derived from host Hb using iron-acquisition systems. Corynebacterium diphtheriae, a pathogen of diphtheria, conducts iron/heme-dependent regulatory ChrS/ChrA systems. In the present study, the ChrS protein was solubilized and purified from the membranes of an Escherichia coli overproducer, and then incorporated into Nanodiscs. The reconstituted ChrS protein exhibited direct and specific heme recognition via His21 in its first transmembrane region, hemedependent autophosphorylation and phosphoryltransfer to ChrA.