Component of the SOS system and an inhibitor of cell division. Accumulation of SulA causes rapid cessation of cell division and the appearance of long, non-septate filaments. In the presence of GTP, binds a polymerization-competent form of FtsZ in a 1:1 ratio, thus inhibiting FtsZ polymerization and therefore preventing it from participating in the assembly of the Z ring. This mechanism prevents the premature segregation of damaged DNA to daughter cells during cell division. Interacts with FtsZ. By DNA damage, as part of the SOS response. Is rapidly cleaved and degraded by the Lon protease once DNA damage is repaired. Belongs to the SulA family.