Translocation and specific cleavage of bacteriophage T7 DNA in vivo by EcoKI
Translocation and specific cleavage of bacteriophage T7 DNA in vivo by EcoKI
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DOI：
10.1073/pnas.96.22.12430
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发表时间：
1999-10-26
影响因子：
11.1
通讯作者：
Molineux, IJ
中科院分区：
文献类型：
--
作者：
García, LR;Molineux, IJ
噬菌体T7 0.3突变体的感染含有I型限制酶Ecoki Ecoki，导致在基因组进入的后期和DNA复制期间受到限制有一个想法，即Ecoki会通过自身双向易位，并在两个酶时切割分子碰撞。从噬菌体lambda粒子中快速射出0.3（+）T7基因组会导致ECOKI感染DNA降解，表明正常的T7 DNA易位过程延迟了限制。插入基因组左端的独特识别位点使Ecoki可以充当分子运动，并将其余39千座T7 DNA转移到细胞中。
Infection of Escherichia coli containing the type I restriction enzyme EcoKI by bacteriophage T7 0.3 mutants leads to restriction during the late stages of genome entry and during DNA replication, Patterns of cleavage in vivo suggest that some cutting occurs near the midpoint of two recognition sites, consistent with the idea that EcoKI translocates DNA bidirectionally through itself and cuts when two enzyme molecules collide. Rapid ejection of a 0.3(+) T7 genome from a bacteriophage lambda particle results in degradation of the infecting DNA by EcoKI, showing that the normal T7 DNA translocation process delays restriction. A unique recognition site inserted at the genomic left end allows EcoKI to function as a molecular motor and to translocate the remaining 39 kilobases of T7 DNA into the cell.