Perkins J D, Heath J D, Sharma B R, Weinstock G M
Department of Biochemistry and Molecular Biology, University of Texas Medical School, Houston 77225.
J Mol Biol. 1993 Jul 20;232(2):419-45. doi: 10.1006/jmbi.1993.1401.
Complete XbaI and BlnI cleavage maps of Escherichia coli K-12 strain MG1655 are presented, along with a comparison of the physical map of MG1655 with that of five other K-12 strains. We have mapped 35 XbaI cleavage sites generating 35 fragments ranging in size from 8 kb to 432 kb using methods similar to those used previously for the NotI and SfiI maps of MG1655. The applicability of the MG1655 map to other strains of E. coli K-12 was assessed by comparing the NotI, SfiI and XbaI digestion patterns of EMG2, W1485, W3110, AB1157 and MC4100 with those of MG1655. The variability between strains, some of which are separated by numerous steps of mutagenic treatment, is readily detectable by pulsed-field gel electrophoresis. A model is presented to account for the differences between the strains on the basis of simple insertions, deletions and, in one case, an inversion. Insertions and deletions ranging in size from 1 kb to 86 kb are suggested by this model. Several of the larger features have previously been characterized and some of the smaller rearrangements can potentially account for previously reported genetic features of these strains. The various features localized in these strains were used to place 9 of the 17 BlnI fragments on the E. coli physical map. The remaining fragments were placed by hybridization experiments similar to those used for the NotI, SfiI and XbaI maps. In this way, the complete BlnI map was constructed. The cleavage sites for XbaI and BlnI were assigned coordinates based on EcoMap6 developed by Rudd et al. The XbaI and BlnI maps of MG1655 presented here, when combined with the NotI (22 sites) and SfiI (31 sites) maps of MG1655 previously published, bring the total number of mapped rare restriction sites in MG1655 to 105. The strain comparison analysis shows that this map is readily adaptable for use with other K-12 strains.
本文展示了大肠杆菌K-12菌株MG1655完整的XbaI和BlnI酶切图谱，并将MG1655的物理图谱与其他五个K-12菌株的图谱进行了比较。我们使用了与之前构建MG1655的NotI和SfiI图谱类似的方法，绘制了35个XbaI酶切位点，产生了35个片段，大小从8 kb到432 kb不等。通过比较EMG2、W1485、W3110、AB1157和MC4100与MG1655的NotI、SfiI和XbaI酶切模式，评估了MG1655图谱对其他大肠杆菌K-12菌株的适用性。通过脉冲场凝胶电泳很容易检测到菌株之间的变异性，其中一些菌株经过了多次诱变处理。本文提出了一个模型，以解释基于简单插入、缺失以及一例倒位的菌株间差异。该模型表明存在大小从1 kb到86 kb的插入和缺失。一些较大的特征先前已被表征，一些较小的重排可能解释了这些菌株先前报道的遗传特征。这些菌株中定位的各种特征被用于将17个BlnI片段中的9个定位到大肠杆菌物理图谱上。其余片段通过与用于NotI、SfiI和XbaI图谱类似的杂交实验进行定位。通过这种方式，构建了完整的BlnI图谱。基于Rudd等人开发的EcoMap6，为XbaI和BlnI的酶切位点分配了坐标。本文展示的MG1655的XbaI和BlnI图谱，与之前发表的MG1655的NotI（22个位点）和SfiI（31个位点）图谱相结合，使MG1655中已定位的稀有限制酶切位点总数达到105个。菌株比较分析表明该图谱很容易适用于其他K-12菌株。
