title: C-shaped cells caused by expression of an ftsA mutation in Escherichia coli.
abstract: A plasmid, pDLL4, was isolated from a Tn5tac1 mutagenesis experiment with plasmid pZAQ. When pDLL4 was transformed into wild-type rod-shaped cells, it caused cells in the population to become curved (C-shaped or convoluted). The Tn5tac1 transposon was integrated within the carboxyl end of the ftsA gene in pDLL4. This mutation was designated ftsAc. Subcloning ftsAc DNA into another plasmid vector verified that the curved-cell phenotype was caused by the expression of this altered gene. DNA sequence analysis of the ftsAc mutation revealed that the transposition event changed the DNA so that the last 28 amino acids of the FtsA protein were lost and 5 new amino acids were added. A radioactive peptide band corresponding to this truncated FtsAc protein was identified by a T7 promoter-T7 polymerase protein labeling system. Observations of thin sections of these curved cells with an electron microscope revealed aggregates of striated cylindrical structures traversing the cytoplasm. The ends of these aggregates appear to be at or near the cell membrane. The linear periodicity of the cylinders was approximately 11 nm, and the diameter of a cylinder was about 15 nm. Aggregates of as many as five cylinders were arrayed diagonally to the long axis of the curved cells, a finding that suggests that some type of internal organization may be causing the curved cell shape.
authors.affiliation: Department of Microbiology, Louisiana State University, Baton Rouge.
authors.forename: R C
authors.initials: RC
authors.lastname: Gayda
authors.forename: M C
authors.initials: MC
authors.lastname: Henk
authors.forename: D
authors.initials: D
authors.lastname: Leong
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D004926:Escherichia coli / Q000166:cytology* / Q000235:genetics; D029968:Escherichia coli Proteins; D015870:Gene Expression; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids; D015183:Restriction Mapping
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C065103:FtsA protein, Bacteria; C489310:FtsA protein, E coli