He Bixi, Sachla Ankita J, Ruesewald Sadie B, Kearns Daniel B, Helmann John D
Department of Microbiology, Cornell University, Ithaca, New York, USA.
Department of Biology, Indiana University, Bloomington, Indiana, USA.
J Bacteriol. 2025 May 22;207(5):e0008825. doi: 10.1128/jb.00088-25. Epub 2025 Apr 16.
TerC family proteins are widely conserved integral membrane proteins with functions related to metal transport. In , the TerC proteins MeeF and MeeY play overlapping roles in the metalation of manganese-requiring membrane and extracellular enzymes. TerC proteins interact with the secretion translocon SecYEG and metalate proteins either during or after protein translocation. Here, we demonstrate that swarming motility is dependent on MeeY. This swarming defect can be complemented extracellularly and is correlated with a loss of surfactin. Surfactin export is mediated by SwrC, an RND family efflux pump previously shown to interact with MeeY in co-immunoprecipitation studies. The amendment of the growth medium with manganese has long been known to enhance surfactin production. We suggest a model in which surfactin export is enhanced by the MeeY-dependent metalation of the surfactin lipopeptide during export.IMPORTANCE produces surfactin, a powerful detergent-like compound that functions in intercellular communication, surface motility, and as a broad-spectrum antimicrobial agent. Production of surfactin, a cyclic lipopeptide, depends on a non-ribosomal peptide synthase followed by export by SwrC, a member of the resistance-nodulation-cell division (RND) family of export proteins. Here, we demonstrate that surfactin production additionally requires MeeY, a TerC family membrane protein that exports manganese ions to support the function of secreted and membrane metalloenzymes. We propose that MeeY interacts with SwrC to facilitate metal binding to the surfactin lipopeptide during export from the cell. These results may explain the long-appreciated role that divalent metal ions play in surfactin production during industrial fermentation.
TerC家族蛋白是广泛保守的整合膜蛋白,其功能与金属转运有关。在[具体内容缺失]中,TerC蛋白MeeF和MeeY在需要锰的膜蛋白和细胞外酶的金属化过程中发挥重叠作用。TerC蛋白与分泌转运体SecYEG相互作用,并在蛋白质转运期间或之后使蛋白质金属化。在此,我们证明群体游动依赖于MeeY。这种群体游动缺陷可以在细胞外得到补充,并且与表面活性素的丧失相关。表面活性素的输出由SwrC介导,SwrC是一种RND家族外排泵,先前在共免疫沉淀研究中显示与MeeY相互作用。长期以来已知用锰改良生长培养基可增强表面活性素的产生。我们提出了一个模型,其中在输出过程中,表面活性素的输出通过表面活性素脂肽的MeeY依赖性金属化而增强。重要性[具体内容缺失]产生表面活性素,这是一种强大的类似洗涤剂的化合物,在细胞间通讯、表面运动以及作为广谱抗菌剂中发挥作用。环状脂肽表面活性素的产生依赖于非核糖体肽合成酶,随后由抗性-固氮-细胞分裂(RND)家族输出蛋白成员SwrC输出。在此,我们证明表面活性素的产生还需要MeeY,MeeY是一种TerC家族膜蛋白,它输出锰离子以支持分泌型和膜金属酶的功能。我们提出MeeY与SwrC相互作用,以促进在从细胞输出期间金属与表面活性素脂肽的结合。这些结果可能解释了二价金属离子在工业发酵过程中表面活性素产生中早已为人所知的作用。