Bouquin N, Tempête M, Holland I B, Séror S J
Insitut de Génétique et Microbiologie, CNRS URA 1354, Université Paris XI, Orsay, France.
Mol Gen Genet. 1995 Mar 10;246(5):628-37. doi: 10.1007/BF00298970.
A mutant, tfpA1, resistant to the calmodulin inhibitor trifluoroperazine (TFP) at 30 degrees C, was isolated in Escherichia coli. The mutant showed a reduced growth rate at 30 degrees C and was temperature sensitive (ts) at 42 degrees C for growth, forming short filaments. The mutation was mapped to the 24 min region of the chromosome and the gene was cloned by complementation of the ts defect. Subsequent subcloning, complementation analysis, marker rescue mapping and sequencing, identified tfpA as fabD, encoding the 35 kDa, malonyl-coenzyme A transacylase (MCT) enzyme, required for the initial step in the elongation cycle for fatty acid biosynthesis. Resistance to TFP may result from altered permeability of the cell envelope, although the mutant remained sensitive to other calmodulin inhibitors and to other antibacterial agents. Alternatively, resistance may be more indirect, resulting from alterations in intracellular Ca++ levels which affect the activity of the TFP target in some way.
在大肠杆菌中分离出一株对钙调蛋白抑制剂三氟拉嗪（TFP）在30℃具有抗性的突变体tfpA1。该突变体在30℃时生长速率降低，在42℃时对生长温度敏感（ts），形成短丝。该突变被定位到染色体的24分钟区域，并通过ts缺陷的互补作用克隆了该基因。随后的亚克隆、互补分析、标记拯救定位和测序，确定tfpA为fabD，编码35 kDa的丙二酰辅酶A转酰基酶（MCT），这是脂肪酸生物合成延伸循环初始步骤所必需的酶。对TFP的抗性可能是由于细胞膜通透性改变所致，尽管该突变体对其他钙调蛋白抑制剂和其他抗菌剂仍敏感。或者，抗性可能更间接，是由于细胞内Ca++水平的改变以某种方式影响了TFP靶点的活性。
