Open AccessStrand-specific break near the origin of bacteriophage P2 DNA replication.
Author(s) -
Dhruba K. Chattoraj
Publication year - 1978
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.75.4.1685
Subject(s) - dna replication , dna , biology , rolling circle replication , control of chromosome duplication , dna polymerase ii , bacteriophage , dna clamp , prokaryotic dna replication , replication factor c , origin of replication , eukaryotic dna replication , microbiology and biotechnology , biophysics , genetics , escherichia coli , gene , polymerase chain reaction , reverse transcriptase
Membrane-associated P2 DNA isolated early after infection under conditions that block replication (amB in phage and rep in Escherichia coli C) was analyzed by electron microscopy. Most DNA was in the form of relaxed circles (40%) and circles with short single-stranded tails (60%). When this DNA was hybridized with separate strands of linear P2 Hy dis DNA (which provides suitable reference points along the heteroduplex molecules), an interruption was located near the previously mapped origin of P2 DNA replication in one specific strand. The same strand was sometimes extended in the direction consistent with the unidirectional mode of P2 DNA replication. Similar conclusions were reached when the intracellular DNA was analyzed after partial denaturation. These results are consistent with the rolling circle mode of DNA replication.