Open AccessDetermination of the nick site at oriT of IncI1 plasmid R64: global similarity of oriT structures of IncI1 and IncP plasmids
Author(s) -
Nobuhisa Furuya,
Teruya Komano
Publication year - 1991
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.173.20.6612-6617.1991
Subject(s) - biology , plasmid , microbiology and biotechnology , dna , cleavage (geology) , phosphodiester bond , rolling circle replication , primer (cosmetics) , origin of replication , dna replication , genetics , gene , rna , chemistry , paleontology , fracture (geology) , organic chemistry
The nick site at the origin of transfer, oriT, of IncI1 plasmid R64 was determined. A site-specific and strand-specific cleavage of the phosphodiester bond was introduced during relaxation of the oriT plasmid DNA. Cleavage occurred between 2'-deoxyguanosine and thymidine residues, within the 44-bp oriT core sequence. The nick site was located 8 bp from the 17-bp repeat. A protein appeared to be associated with the cleaved DNA strand at the oriT site following relaxation. This protein was observed to bind to the 5' end of the cleaved strand, since the 5'-phosphate of the cleaved strand was resistant to the phosphate exchange reaction by polynucleotide kinase. In contrast, the 3' end of the cleaved strand appeared free, since it was susceptible to primer extension by DNA polymerase I. The global similarity of the oriT structures of IncI1 and IncP plasmids is discussed.