Time-lapse imaging of conjugative plasmid transfer in Streptomyces revealed intriguing insights into the unique two-step conjugation process of this Gram⁺ mycelial soil bacterium. Differentially labelling of donor and recipient strains with distinct fluorescent proteins allowed the visualization of plasmid transfer in living mycelium. In nearly all observed matings, plasmid transfer occurred when donor and recipient hyphae made intimate contact at the lateral walls. Plasmid transfer does not involve a complete fusion of donor and recipient hyphae, but depends on a pore formed by the FtsK-like DNA translocase TraB. Following the initial transfer at the contact site of donor and recipient, the plasmids spread within the recipient mycelium by invading neighboring compartments, separated by cross walls. Intra-mycelial plasmid spreading depends on a septal cross wall localized multi-protein DNA translocation apparatus consisting of TraB and several Spd proteins and is abolished in a spd mutant. The ability to spread within the recipient mycelium is a crucial adaptation to the mycelial life style of Streptomyces, potentiating the efficiency of plasmid transfer.

在接合质粒转移延时成像链霉菌显示有趣的见解此革兰的独特的两步骤结合方法⁺菌丝土壤细菌。用不同的荧光蛋白对供体和受体菌株进行不同的标记，可以观察到活菌丝体中质粒的转移。在几乎所有观察到的交配中，当供体和受体菌丝在侧壁上紧密接触时，质粒转移就会发生。质粒转移不涉及供体和受体菌丝的完全融合，而是取决于由FtsK样DNA转位酶TraB形成的孔。在供体和受体的接触位点进行初始转移后，质粒通过侵入被隔壁隔开的相邻隔室，在受体菌丝体内扩散。菌丝内质粒的扩散取决于由TraB和几种Spd蛋白质组成的隔壁跨壁局部多蛋白质DNA易位装置，并在spd突变体。在受体菌丝体内传播的能力是对链霉菌菌丝生活方式的关键适应，可增强质粒转移的效率。