Open AccessRepetitive DNA replication of the incomplete genomes of phage T4 petite particles.
Author(s) -
Andrzej W. Kozinski,
A. H. Doermann
Publication year - 1975
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.72.5.1734
Subject(s) - genome , dna , dna replication , biology , replication (statistics) , replicate , rolling circle replication , genetics , bacteriophage , computational biology , gene , virology , escherichia coli , mathematics , statistics
The genomes of petite T4 phage particles presumably cannot circularize because they are deficient for a significant terminal segment and hence not terminally redundant like normal T4 genomes. Combined density- and 32P-labeling shows that the majority of such deficient DNA molecules can nevertheless replicate their entire length. Furthermore, the density-shift technique shows that replicated parental strands can exchange their partners for new light strands, indicating that noncircularized T4 DNA molecules replicate repeatedly. When taken together with previously published data, these results indicate that T4 replication is bidirectional from multiple, genetically fixed points of origin. Rolling circle models can, therefore, not be considered as an essential mechanism for the early rounds of T4 replication.