Cell division protein whose function is related to the generation of a transient cell wall structure. Function is linked to the late stages of cell division. Localizes to the septal ring prior to the onset of constriction and remains at the midcell throughout cytokinesis. Recruitment to the septal ring requires FtsZ, but not downstream division proteins. The OapA domain binds peptidoglycan. Deletion of the gene has no discernible impact on morphology or cell size. YtfB/dedD double mutant grows as filamentous cells. Overproduction causes cells to filament, most likely by disrupting FtsZ ring assembly. Belongs to the OapA family. Extended N-terminus.