Baylor N W, Williams A L, Cofie N
Mol Gen Genet. 1983;191(3):347-52. doi: 10.1007/BF00425744.
A series of lambda defective ilvC specialized transducing phage has been isolated which carry regions of isoleucine and valine structural and regulatory genes derived from the ilv cluster at minute 83 on the linkage map of the chromosome of Escherichia coli K-12. The ilv genes carried by these phages and their order have been determined by transduction of auxotrophs. The ilvC+ lysogen of an ilvC- strain gave rise, after heat induction of the lysogen, to transducing particles which carried the wild-type allele of the cya-marker. Further experiments have shown that the lambda defective ilvC phages were able to cotransduce a rho-15ts mutation as well as a rep-5 mutation. Hence, the order of the clockwise excision of the ilv cluster was found to be ilvC-rho-rep-cya. Enzyme levels in strains carrying the lambda defective ilvC phages indicated the the ilvC gene was not altered by the insertion of lambda into the ilv cluster. The isolation and digestion of lambda defective ilvC DNA by EcoRI and HindIII restriction endonucleases demonstrated that the specialized transducing phages carried part of the genome from the E. coli K-12 chromosome.
已经分离出一系列λ缺陷型ilvC特异性转导噬菌体，它们携带源自大肠杆菌K-12染色体连锁图上第83分钟处ilv簇的异亮氨酸和缬氨酸结构及调控基因区域。这些噬菌体携带的ilv基因及其顺序已通过营养缺陷型的转导来确定。ilvC-菌株的ilvC+溶原菌在对溶原菌进行热诱导后，产生了携带cya标记野生型等位基因的转导颗粒。进一步的实验表明，λ缺陷型ilvC噬菌体能够共转导rho-15ts突变以及rep-5突变。因此，发现ilv簇顺时针切除的顺序为ilvC-rho-rep-cya。携带λ缺陷型ilvC噬菌体的菌株中的酶水平表明，ilvC基因并未因λ插入ilv簇而改变。用EcoRI和HindIII限制性内切酶对λ缺陷型ilvC DNA进行分离和消化表明，这些特异性转导噬菌体携带了来自大肠杆菌K-12染色体的部分基因组。
