FTSZ RING FORMATION IN FTS MUTANTS

The formation of FtsZ rings (Z rings) in various fts mutants was exami ned by immunoelectron microscopy and immunofluorescence. In two temper ature-sensitive ftsZ mutants which form filaments with smooth morpholo gy, the Z ring was unable to form, In ftsA, ftsI, and ftsQ mutants, wh ich form filaments with an indented morphology, Z rings formed but the ir contraction was blocked. These results indicate that fully function al ftsA, ftsQ, and ftsI genes are not required for Z-ring formation an d are unlikely to have a role in localization of the Z ring. The resul ts also suggest that one function of the Z ring is to localize the act ivity of other fts gene products.