Spontaneous deletions in the TOL plasmid pWW20 which give rise to the B3 regulatory mutants of Pseudomonas putida MT20.
Spontaneous deletions in the TOL plasmid pWW20 which give rise to the B3 regulatory mutants of Pseudomonas putida MT20.
复制标题
TOL 质粒 pWW20 中的自发缺失产生恶臭假单胞菌 MT20 的 B3 调节突变体。
DOI：
10.1099/00221287-128-7-1385
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
P. Williams
中科院分区：
文献类型：
--
作者：
R. Pickup;P. Williams
来自恶臭假单胞菌MT 20的TOL质粒pWW 20的大小，通过限制性内切酶水解后的琼脂糖电泳凝胶分析测定，为270-280个内切酶对（kb）。在苯甲酸盐上生长期间，MT 20分离质粒调节基因xylS中携带突变的菌株;这些所谓的B3菌株保留在间二甲苯（Mxy+）上生长的能力，但不能在其代谢物间甲苯甲酸盐（Mtol-）上生长，并且也失去了转移质粒（Tra-）的能力。对来自7个独立分离的分离体的质粒DNA的限制性内切酶分析表明，pWW 20经历了90-100 kb的广泛缺失。所有缺失的质粒都丢失了一个约72-80 kb的共同DNA核心，但在A类突变体中，缺失在该核心的一端延伸，而在B类突变体中，缺失在另一端延伸。A类和B类突变体在间二甲苯上的生长速率也不同，这是由于它们的质粒编码的分解代谢酶的表达水平不同。这表明，一个额外的基因，参与调节基因表达水平，是位于该地区独特的删除B类突变体。
The size of the TOL plasmid pWW20 from Pseudomonas putida MT20, as measured by analysis of agarose electrophoresis gels after restriction endonuclease hydrolysis, was 270-280 kilobase pairs (kb). During growth on benzoate, MT20 segregates strains carrying mutations in the plasmid regulatory gene xylS; these so-called B3 strains retain the ability to grow on m-xylene (Mxy+) but do not grow on its metabolite m-toluate (Mtol-) and have also lost the ability to transfer the plasmid (Tra-). Analysis of restriction digests of plasmid DNA from seven such segregants, independently isolated, showed that pWW20 had undergone extensive deletions of 90-100 kb. All the deleted plasmids had lost a common core of DNA, of about 72-80 kb, but in class A mutants the deletion extended at one end of this core and in class B mutants at the other end. Class A and B mutants also differed in their rate of growth on m-xylene as a result of differences in the level of expression of their plasmid-coded catabolic enzymes. This suggests that an additional gene, involved in regulating levels of gene expression, is located in the region uniquely deleted in the class B mutants.