Luthman H, Osterlund M, Magnusson G
Nucleic Acids Res. 1984 Oct 11;12(19):7503-515. doi: 10.1093/nar/12.19.7503.
The effect of base pair substitutions on the function of the polyoma virus origin of DNA replication was studied. The mutations were all C-G to T-A transitions, induced by bisulfite treatment of recombinant DNA molecules. The mutagenesis was directed to short single-stranded gaps in duplex DNA, or to loops in heteroduplex molecules. Modification of a 34 base pair sequence of dyad symmetry led to cis-acting inhibition of viral DNA synthesis, ranging from slight defects to total inactivation. One of the mutants was temperature sensitive. Mutants with base changes in an adjacent DNA segment, including an 18 base pair long purine-pyrimidine tract, had similar, but less severe, deficiences. In contrast to the effect of mutations in the homologous region of the simian virus 40 genome, there was no strict relationship between mutation of the putative large T-antigen-binding base sequence GPuGGC and defective viral DNA synthesis.
研究了碱基对替换对多瘤病毒DNA复制起点功能的影响。这些突变均为C-G到T-A的转换,由亚硫酸氢盐处理重组DNA分子诱导产生。诱变作用针对双链DNA中的短单链缺口或异源双链分子中的环。对具有二元对称性的34个碱基对序列的修饰导致病毒DNA合成的顺式作用抑制,范围从轻微缺陷到完全失活。其中一个突变体是温度敏感型的。在相邻DNA片段中发生碱基变化的突变体,包括一个18个碱基对长的嘌呤-嘧啶序列,具有相似但不太严重的缺陷。与猿猴病毒40基因组同源区域突变的影响相反,假定的大T抗原结合碱基序列GPuGGC的突变与有缺陷的病毒DNA合成之间没有严格的关系。