Kumar S
J Bacteriol. 1976 Feb;125(2):545-55. doi: 10.1128/jb.125.2.545-555.1976.
Several spontaneous cya and crp mutants of Escherichia coli have been selected as clones simultaneously resistant to phage lambda and nalidixic acid and characterized. Both cya and crp mutants have been found to grow as cocci with increased doubling times. They have increased resistance to some mutagens (methylmethanesulfonate, ultraviolet light, gamma rays), antibiotics (nalidixic acid, ampicillin), phages (lambda, T6), sublethal heat and hypotonic shock, and decreased resistance to neutral detergents (sodium dodecyl sulfate, sodium deoxycholate), a protein synthesis inhibitor (streptomycin), and a respiratory inhibitor (sodium azide). The nature of changes in cell parameters indicate fundamental alterations in the envelope structure of the cya and crp mutant cells. The new cya and crp mutants have been found to be multiply carbohydrate negative and nonmotile in conformity with similar previously isolated mutants. Studies of revertants and phi80 cya+ and phi80 cya transductants indicated that the pleiotropic phenotype is related to a single mutational event at the cya or the crp locus in the mutants.
已筛选出几种大肠杆菌的自发cya和crp突变体,作为对噬菌体λ和萘啶酸同时具有抗性的克隆,并对其进行了表征。已发现cya和crp突变体均以球菌形式生长,倍增时间增加。它们对某些诱变剂(甲基磺酸甲酯、紫外线、γ射线)、抗生素(萘啶酸、氨苄青霉素)、噬菌体(λ、T6)、亚致死热和低渗休克的抗性增加,而对中性去污剂(十二烷基硫酸钠、脱氧胆酸钠)、蛋白质合成抑制剂(链霉素)和呼吸抑制剂(叠氮化钠)的抗性降低。细胞参数变化的性质表明cya和crp突变体细胞的包膜结构发生了根本性改变。已发现新的cya和crp突变体与先前分离的类似突变体一致,表现为多种碳水化合物阴性且无运动性。对回复体以及phi80 cya+和phi80 cya转导子的研究表明,多效性表型与突变体中cya或crp基因座的单个突变事件有关。