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. The effect of overexpression of SulA is neutralized by antitoxin CbeA (yeeU) (PubMed:22515815). Interacts with FtsZ. By DNA damage, as part of the SOS response, repressed by LexA (PubMed:3297925). Induced 8-fold by hydroxyurea (at protein level) (PubMed:20005847). Is rapidly cleaved and degraded by the Lon protease once DNA damage is repaired. Belongs to the SulA family.