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:1981
卷号:78
期号:4
页码:2184-2188
DOI:10.1073/pnas.78.4.2184
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:We have developed a method for introducing mutations into the adenovirus type 2 genome at predetermined sites. Specific mutations are introduced into segments of the viral genome cloned in bacteria by using plasmid vectors. The chimeric DNA is used to construct viral mutants by cotransfection with two viral DNA segments derived from both ends of the viral genome, each of which has overlapping sequence homology with the cloned viral DNA segment. To illustrate this procedure, we cloned a large restriction fragment [EcoRI fragment A, map position (mp) 0--58.5] by using plasmid vector pBR322, and a small deletion mutation was introduced at the BamHI cleavage site located within the VA-RNAI gene (mp 29 at residue +75 on VA-RNAI gene). The mutated DNA was then used to construct viral mutants by cotransfection into human cells with the adenovirus type 2 DNA--protein complex digested with Sal I. In vivo recombination occurred via overlapping sequences between the cloned EcoRI fragment A and Sal I-digested DNA--protein complex at two sites, mp 0--25 (i.e., within Sal I fragment B) and mp 45--58.5 (i.e., overlapping sequences between Sal I fragment A and EcoRI fragment A), generating infectious DNA molecules with intact ends. The viral mutant grows as well as the wild type in KB cells and induces the synthesis of smaller VA-RNAI but normal-size VA-RNAII.