Toxic component of one of 6 LXG toxin-immunity modules in this strain. They promote kin selection, mediate competition in biofilms, and drive spatial segregation of different strains, indicating that LXG toxins may help avoid warfare between strains in biofilms. Mediates intercellular competition during biofilm formation; disruption of the operon disadvantages the bacteria, but overexpression of the cognate immunity protein restores growth in competition with wild-type. Overexpression alone in situ causes growth arrest but not cell lysis, a large decrease in chromosomal DNA content and the production of anucleate cells. No effect is seen on rRNA. Co-overexpression with cognate immunity protein YezG does not cause growth arrest. The toxic effect is dependent on the epsA and tapA operons which are required for biofilm formation (PubMed:34280190). Binds DNA in the presence and absence of YezG (By similarity). Interacts with cognate immunity protein YezG but not with non-cognate immunity protein YobK. The interaction probably inhibits the toxic activity of YeeF. Present in detergent-resistant membrane (DRM) fractions that may be equivalent to eukaryotic membrane rafts; these rafts include proteins involved in signaling, molecule trafficking and protein secretion (PubMed:22882210). Delivery to target cells requires the type VII secretion system (T7SS) and YukE (PubMed:34280190). Expressed on rich and minimal solid media likely in early stationary phase; dependent on DegSU. Not expressed in liquid LB, but only under conditions that promote biofilm formation. Deletion of the yeeF-yezG operon has no visible growth phenotype, however it is out-competed by wild-type cells. In the N-terminal section; belongs to the LXG family. Was originally suggested to be an RNase.