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：21
页码：6598-6602
DOI：10.1073/pnas.79.21.6598
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A plasmid was constructed that facilitates the cloning and expression of open reading frame DNA. A DNA fragment containing a bacterial promoter and the amino terminus of the cI gene of bacteriophage lambda was fused to an amino-terminally deleted version of the lacZ gene. An appropriate cloning site was inserted between these two fragments such that a frameshift mutation was introduced upstream of the lacZ-encoding DNA. This cloning vehicle produces a relatively low level of beta-galactosidase activity when introduced into Escherichia coli. The insertion of foreign DNA at the cloning site can reverse the frameshift mutation and generate plasmids that produce a relatively high level of beta-galactosidase activity. A large fraction of these plasmids produce a fusion protein that has a portion of the lambda cI protein at the amino terminus, the foreign protein segment in the middle, and the lacZ polypeptide at the carboxyl terminus. The production of a high level of beta-galactosidase and a large fusion polypeptide guarantees the cloning of a DNA fragment with at least one open reading frame that traverses the entirety of the fragment. Hence, the method can identify, clone, and express (as part of a larger fusion polypeptide) open reading frame DNA from among a large collection of DNA fragments.
