Regulation of Bacterial Cell Division: Genetic and Phenotypic Analysis of Temperature-Sensitive, Multinucleate, Filament-Forming Mutants of Escherichia coli

Abstract

Three mutants of Escherichia coli K-12 which form filaments during 42 C incubation have been characterized. The mutant strains AX621, AX629, and AX655 continued to grow and to synthesize deoxyribonucleic acid at 42 C for 150 to 180 min, after which time growth ceased. When cultures of the mutants were transferred from 42 to 28 C, septation of the filaments began after a 25to 30-min period and continued at a greater than normal rate until no filaments remained. Addition of chloramphenicol at the time of transfer from 42 to 28 C prevented cell division in strain AX655 and caused lysis of strains AX621 a;;d AX629. The temperature sensitivity mutation in each strain mapped near leu. For strain AX621, the mutation was specifically located between leu and nadC by P1 transduction. Properties of these strains are compared with those of other cell division mutants.

Division of temperature-sensitive Streptococcus faecium mutants after return to the permissive temperature

“…Our data differ in several respects from those reported previously for rod-shaped organisms (1)(2)(3)(8)(9)(10). First is the inability of class 1, 2, and 3 mutants to recover after incubation at 42°C for periods of over 30 to 45 min (Fig.…”

“…This response suggests that a potential for cell division is accumulated at the nonpermissive temperature. The division of filaments may be inhibited (1,3,8,10) or not (2,9,10) by chloramphenicol, suggesting variability in a requirement for new protein synthesis. Regrowth of temperature-sensitive division mutants can be used to analyze the nature of the division block.…”

“…Rod-shaped, temperature-sensitive division mutants recovering from nonpermissive conditions usually exhibit an abrupt fragmentation of filaments subsequent to the temperature shift-down (1)(2)(3)(8)(9)(10). This response suggests that a potential for cell division is accumulated at the nonpermissive temperature.…”

Identification of the Escherichia coli cell division gene sep and organization of the cell division-cell envelope genes in the sep-mur-ftsA-envA cluster as determined with specialized transducing lambda bacteriophages

“…Hirota et al (8) later proposed that this locus be designated ftsA to distinguish it from other fts loci around the chromosome. A mutant that carries the cell division mutation 2158(Ts) was descibed by Allen et al (1); the 2158(Ts) mutation was mapped 0.5 to 0.6 min to the right of leu by P1 tnI uction (25).…”

Bacteriophage Mu-1-induced mutation to mutT in Escherichia coli

“…The insertion of phage Mu into an operon has a strong polar effect on the expression of genes distal to the insertion (23). Genes affecting cell division (1,16), resistance to sodium azide and phenethyl alcohol (26), and the level of DNA polymerase II (4) lie near mutT. If mutT is in the same operon as any of these genes, a polar effect may be detectable in mut-49 strains.…”