期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1982
卷号：79
期号：6
页码：1766-1770
DOI：10.1073/pnas.79.6.1766
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We have constructed a hybrid pKC30-uvrA plasmid (pGHY5003) in which transcription of the uvrA gene can be induced under pL control to amplify the uvrA gene product to 7% of cellular protein. To construct pGHY5003, we developed a genetic selection using the basal level of expression (30 degrees C) from pL in thermosensitive cI857 lysogens to isolate appropriately tailored repair genes inserted at the Hpa I site of pKC30 from recombinant DNA mixtures with a variety of products. In addition, a post-UV-irradiation radiolabeling method was adapted to screen inserts for temperature-inducible polypeptide synthesis directed by transcription under pL control rapidly. This should prove generally useful for isolating genes inserted at the Hpa I site of plasmid pKC30 with the following characteristics: (i) genetically functional hybrid plasmids selected from a large population of exonucleolytically tailored fragments ligated into Hpa I of pKC30 and (ii) production of high-level amplification for the gene product of interest by screening for post-UV-irradiation temperature inducibility of polypeptides synthesized from hybrid plasmids. The level of amplification obtained for the uvrA gene product from pGHY5003 is approximately 10,000-fold higher than estimates of the level of uvrA protein in logarithmic phase Escherichia coli.
