Jones M, Wagner R, Radman M
Genetics. 1987 Apr;115(4):605-10. doi: 10.1093/genetics/115.4.605.
Heteroduplexes with single base pair mismatches of known sequence were prepared by annealing separated strands of bacteriophage lambda DNA and used to transfect Escherichia coli. A series of transition (G:T and A:C) and transversion (G:A and C:T) mismatches located throughout most of the bacteriophage lambda cI gene has been examined. The results suggest that the transition mismatches are generally better repaired than the transversion mismatches and that, at least for the transversion mismatches studied, repair efficiency increases with increasing G:C content in the neighboring nucleotide sequence. This specificity of the E. coli mismatch repair system can account, in part, for the similar frequencies of base substitution mutations throughout the E. coli genome.
通过对噬菌体λ DNA 的单链进行退火处理,制备出具有已知序列单碱基对错配的异源双链体,并用于转染大肠杆菌。已对噬菌体λ cI 基因大部分区域的一系列转换(G:T 和 A:C)和颠换(G:A 和 C:T)错配进行了检测。结果表明,转换错配通常比颠换错配修复得更好,并且至少对于所研究的颠换错配而言,修复效率随着相邻核苷酸序列中 G:C 含量的增加而提高。大肠杆菌错配修复系统的这种特异性可以部分解释大肠杆菌基因组中碱基替代突变的相似频率。