Translocation and specific cleavage of bacteriophage T7 DNA in vivo by EcoKI
AUTOR(ES)
García, L. René
FONTE
The National Academy of Sciences
RESUMO
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 λ 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.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=22939Documentos Relacionados
- Interaction of the ocr gene 0.3 protein of bacteriophage T7 with EcoKI restriction/modification enzyme
- Bacteriophage T7 defective in the gene 6 exonuclease promotes site-specific cleavages of T7 DNA in vivo and in vitro.
- Mutagenesis of bacteriophage T7 and T7 DNA by alkylation damage.
- Modulation of EcoKI restriction in vivo: role of the lambda Gam protein and plasmid metabolism.
- S-adenosyl methionine alters the DNA contacts of the EcoKI methyltransferase.