Zinc is a potent antimicrobial component of the innate immune response at the host-pathogen interface. Bacteria subvert or resist host zinc insults by metal efflux pathways that include cation diffusion facilitator (CDF) proteins. The structural and functional examination of this protein class has been limited, with only the structures of the zinc transporter YiiP proteins from E. coli and Shewanella oneidensis described to date. Here, we determine the metal binding properties, solution quaternary structures and three dimensional architectures of the C-terminal domains of the metal transporter CzcD proteins from Cupriavidus metallidurans, Pseudomonas aeruginosa and Thermotoga maritima. We reveal significant diversity in the metal-binding properties and structures of these proteins and discover a potential novel mechanism for metal-promoted dimerization for the Cupriavidus metallidurans and Pseudomonas aeruginosa proteins.

锌是宿主-病原体界面上先天免疫反应的有效抗菌成分。细菌通过包括阳离子扩散促进剂（CDF）蛋白的金属外排途径来破坏或抵抗宿主锌的侵害。该蛋白类别的结构和功能检查受到限制，迄今为止仅描述了来自大肠杆菌和沙伊氏菌的锌转运蛋白YiiP蛋白的结构。在这里，我们确定的金属结合特性，溶液四元结构和三维结构的金属转运体CzcD蛋白的C末端域中的金属铜杯铜绿假单胞菌，铜绿假单胞菌和滨海嗜热菌。。我们揭示了这些蛋白质的金属结合特性和结构中的显着多样性，并发现了金属促铜体和铜绿假单胞菌蛋白金属促进的二聚化的潜在新机制。