Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, NY, 14853-8101, USA.
Nat Commun. 2023 Oct 4;14(1):6186. doi: 10.1038/s41467-023-41896-1.
Cytosolic metalloenzymes acquire metals from buffered intracellular pools. How exported metalloenzymes are appropriately metalated is less clear. We provide evidence that TerC family proteins function in metalation of enzymes during export through the general secretion (Sec-dependent) pathway. Bacillus subtilis strains lacking MeeF(YceF) and MeeY(YkoY) have a reduced capacity for protein export and a greatly reduced level of manganese (Mn) in the secreted proteome. MeeF and MeeY copurify with proteins of the general secretory pathway, and in their absence the FtsH membrane protease is essential for viability. MeeF and MeeY are also required for efficient function of the Mn-dependent lipoteichoic acid synthase (LtaS), a membrane-localized enzyme with an extracytoplasmic active site. Thus, MeeF and MeeY, representative of the widely conserved TerC family of membrane transporters, function in the co-translocational metalation of Mn-dependent membrane and extracellular enzymes.
细胞质金属酶从缓冲的细胞内池中获取金属。然而，对于如何适当金属化分泌的金属酶，我们还不太清楚。本研究提供了证据，证明 TerC 家族蛋白在通过一般分泌（Sec 依赖）途径进行酶分泌时发挥作用。枯草芽孢杆菌菌株缺乏 MeeF（YceF）和 MeeY（YkoY）后，蛋白质的分泌能力降低，分泌蛋白组中的锰（Mn）水平大大降低。MeeF 和 MeeY 与一般分泌途径的蛋白质共纯化，在它们缺失的情况下，FtsH 膜蛋白酶对于生存是必需的。MeeF 和 MeeY 对于 Mn 依赖性脂磷壁酸合酶（LtaS）的有效功能也是必需的，LtaS 是一种具有细胞外活性部位的膜定位酶。因此，MeeF 和 MeeY，作为广泛保守的 TerC 家族膜转运蛋白的代表，在 Mn 依赖性膜和细胞外酶的共易位金属化中发挥作用。
