C-SHAPED CELLS CAUSED BY EXPRESSION OF AN FTSA MUTATION IN ESCHERICHIA-COLI
C-SHAPED CELLS CAUSED BY EXPRESSION OF AN FTSA MUTATION IN ESCHERICHIA-COLI
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DOI：
10.1128/jb.174.16.5362-5370.1992
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发表时间：
1992-08-01
影响因子：
3.2
通讯作者：
LEONG, D
中科院分区：
文献类型：
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作者：
GAYDA, RC;HENK, MC;LEONG, D
质粒 pDLL4 是从质粒 pZAQ 的 Tn5tac1 诱变实验中分离出来的。当 pDLL4 转化为野生型杆状细胞时，它会导致细胞群中的细胞变得弯曲（C 形或卷曲）。 Tn5tac1 转座子整合在 pDLL4 中 ftsA 基因的羧基末端。该突变被命名为 ftsA(c)。将 ftsA(c) DNA 亚克隆到另一个质粒载体中，证实弯曲的细胞表型是由该改变的基因的表达引起的。 ftsA(c) 突变的 DNA 序列分析表明，转座事件改变了 DNA，导致 FtsA 蛋白的最后 28 个氨基酸丢失，并添加了 5 个新氨基酸。通过 t7 启动子-T7 聚合酶蛋白标记系统鉴定出与该截短的 FtsA(c) 蛋白相对应的放射性肽带。用电子显微镜观察这些弯曲细胞的薄片，发现横贯细胞质的条纹圆柱形结构聚集体。这些聚集体的末端似乎位于或靠近细胞膜。圆柱体的线性周期约为11nm，圆柱体的直径约为15nm。多达五个圆柱体的聚集体与弯曲细胞的长轴对角排列，这一发现表明某种类型的内部组织可能导致弯曲细胞形状。
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 ftsA(c). Subcloning ftsA(c) 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 ftsA(c) 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 FtsA(c) 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.