Fig. 8. ComEA_Bs domain architecture, and proposed model of genetic transformation in Gram-positive bacteria.

A ComEA_Bs contains an N-terminal transmembrane region, a previously unidentified OD, and a C-terminal DNA-binding domain. B We have shown that ComEA self-associates using contacts in its ODs. After retraction of the tpilus to bring a loop of DNA into the periplasm, binding of tDNA to the ComEA DNA-binding domains followed by uptake stabilize cell association, while cross-linking of distal DNA segments by binding to adjacent ComEA molecules condenses the incoming tDNA, exerting a pulling force to bring tDNA into the periplasm. Elements of the figure were created with BioRender.com.