Abstract
The packaging of intracellular DNA into heads is a key feature in the morphogenesis of bacteriophage particles. In many phages a preformed empty head precursor, the prohead, is filled with DNA from a concatemeric substrate consisting of tandemly repeated genome lengths1,2. The addition of outer shell proteins completes head formation. The DNA molecules released from particles of the coliphage T1 exist as three major permutations of nucleotide sequence3,4. Such limited permutation can be explained by the modification of Streisinger's ‘headful’ mechanism proposed for phage P225,6. DNA packaging is initiated at a specific site (the pac site) on the concatemeric precursor. While this site is cleaved, subsequent cleavages (headful cleavages) are dependent only on head-filling and are not defined in terms of nucleotide sequence. Headfuls of DNA, consisting of slightly more than a genome length, are packaged in three successive cycles of head-filling to produce the permuted and terminally redundant molecules characteristic of T1 DNA. To elucidate the regulation of this process, we have studied the DNA metabolism of T1 head mutants. We describe here the properties of a mutant in gene 13.3 which is defective for headful cleavage but remains proficient in pac site cleavage. The observation in this mutant that concatemers are degraded to unit-length molecules by repeated pac site cleavage suggests a model of headful packaging in which pac site initiation and processive head-filling compete for the DNA substrate.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Murialdo, H. & Becker, A. Microbiol. Rev. 42, 529–576 (1978).
Earnshaw, W. C. & Casjens, S. R. Cell 21, 319–331 (1980).
Gill, G. S. & MacHattie, L. A. J. Molec. Biol. 104, 505–515 (1976).
Ramsay, N. & Ritchie, D. A. Molec. gen. Genet. 179, 669–675 (1980).
Streisinger, G., Emrich, J. & Stahl, M. M. Proc. natn. Acad. Sci. U.S.A. 57, 292–295 (1967).
Tye, B. K., Huberman, J. A. & Botstein, D. J. Molec. Biol. 85, 501–532 (1974).
Ritchie, D. A. & Joicey, D. H. Virology 103, 191–198 (1980).
Laski, F. & Jackson, E. N. J. molec. Biol. 154, 565–579 (1982).
Martin, D. T. M., Adair, C. A. & Ritchie, D. A. J. gen. Virol. 33, 309–319 (1976).
Casjens, S. R. & Hendrix, R. W. J. molec. Biol. 88, 535–545 (1974).
McClure, S. C. C., MacHattie, L. A. & Gold, M. Virology 54, 1–18 (1973).
Kaiser, D., Syvanen, M. & Masuda, T. J. molec. Biol. 91, 175–186 (1975).
Sternberg, N. & Weisberg, R. J. molec. Biol. 117, 733–759 (1977).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ramsey, N., Ritchie, D. Uncoupling of initiation site cleavage from subsequent headful cleavages in bacteriophage T1 DNA packaging. Nature 301, 264–266 (1983). https://doi.org/10.1038/301264a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/301264a0
This article is cited by
-
A coupled in vitro system for the formation and packaging of concatemeric phage T1 DNA
Molecular and General Genetics MGG (1985)
-
Physical and genetical analysis of bacteriophage T4 generalized transduction
Molecular and General Genetics MGG (1983)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.