Site- and Strand-Specific Nicking at oriT of Plasmid R100 in a Purified System: Enhancement of the Nicking Activity of Tral (Helicase I) with TraY and IHF

摘要: We developed a purified system for reproducing the nicking reaction at site 59 base pairs upstream of TraY protein binding site, sbyA, in oriT region plasmid R100. Nicking occurred efficiently presence plasmid-encoded proteins, TraI and TraY, integration host factor (IHF), Mg2+, but inefficiently Mg2+. The products were complex DNA molecules with covalently linked 5' end nick strand, which is supposed to be transferred during conjugation. same formed alone, indicating that attached protein. Stimulation by IHF, whose has been mapped between indicates bending important formation including proteins oriT.