Abstract
T4 mutants in gene 17 accumulate particles which contain the main head protein in the cleaved form (gp23*) arranged in an unexpanded lattice (empty small particles), together with other expanded capsids (empty large particles). The isolated empty small particles can be transformed in vitro, by lowering the ionic strength, to capsid-like structures. This structural transformaton is not coupled to chemical modification of the structural proteins of the empty small particles. In contrast to unexpanded particles that are easily dissociated, the transformed structures are as resistant to dissociation as other T-even head-related particles with expanded lattice. Furthermore, the transformed particles are able to bind in vitro hoc and soc proteins, rendering capsids indistinguishable from the normal T4 capsids both morphologically and by their stability against denaturing agents. Our results indicate that the in vitro transformation of the empty small particles might mimic important and characteristic aspects of the in vivo maturation of T4 heads, thus suggesting a possible role of the "cleaved but unexpanded" particle in the maturation pathway of the T4 shell.
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- Aebi U., Bijlenga R. K., ten Heggeler B., Kistler J., Steven A. C., Smith P. R. Comparison of the structural and chemical composition of giant T-even phage heads. J Supramol Struct. 1976;5(4):475–495. doi: 10.1002/jss.400050406. [DOI] [PubMed] [Google Scholar]
- Aebi U., van Driel R., Bijlenga R. K., ten Heggeler B., van den Broek R., Steven A. C., Smith P. R. Capsid fine structure of T-even bacteriophages. Binding and localization of two dispensable capsid proteins into the P23* surface lattice. J Mol Biol. 1977 Mar 15;110(4):687–698. doi: 10.1016/s0022-2836(77)80084-3. [DOI] [PubMed] [Google Scholar]
- Casjens S., King J. Virus assembly. Annu Rev Biochem. 1975;44:555–611. doi: 10.1146/annurev.bi.44.070175.003011. [DOI] [PubMed] [Google Scholar]
- Fairbanks G., Jr, Levinthal C., Reeder R. H. Analysis of C14-labeled proteins by disc electrophoresis. Biochem Biophys Res Commun. 1965 Aug 16;20(4):393–399. doi: 10.1016/0006-291x(65)90589-9. [DOI] [PubMed] [Google Scholar]
- Kellenberger E., Bitterli D. Preparation and counts of particles in electron microscopy: application of negative stain in the agarfiltration method. Microsc Acta. 1976 May;78(2):131–148. [PubMed] [Google Scholar]
- Kellenberger E., Eiserling F. A., Boy de la Tour E. Studies on the morphopoiesis of the head of phage T-even. 3. The cores of head-related structures. J Ultrastruct Res. 1967 Dec 12;21(3):335–360. doi: 10.1016/s0022-5320(67)80099-6. [DOI] [PubMed] [Google Scholar]
- Laemmli U. K., Amos L. A., Klug A. Correlation between structural transformation and cleavage of the major head protein of T4 bacteriophage. Cell. 1976 Feb;7(2):191–203. doi: 10.1016/0092-8674(76)90018-0. [DOI] [PubMed] [Google Scholar]
- Laemmli U. K., Favre M. Maturation of the head of bacteriophage T4. I. DNA packaging events. J Mol Biol. 1973 Nov 15;80(4):575–599. doi: 10.1016/0022-2836(73)90198-8. [DOI] [PubMed] [Google Scholar]
- Luftig R. B., Ganz C. Bacteriophage T4 head morphogenesis. IV. Comparison of gene 16-, 17-, and 49-defective head structures. J Virol. 1972 Sep;10(3):545–554. doi: 10.1128/jvi.10.3.545-554.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Showe M. K., Isobe E., Onorato L. Bacteriophage T4 prehead proteinase. II. Its cleavage from the product of gene 21 and regulation in phage-infected cells. J Mol Biol. 1976 Oct 15;107(1):55–69. doi: 10.1016/s0022-2836(76)80017-4. [DOI] [PubMed] [Google Scholar]
- Yanagida M., Ahmad-Zadeh C. Determination of gene product positions in bacteriophage T4 by specific antibody association. J Mol Biol. 1970 Jul 28;51(2):411–421. doi: 10.1016/0022-2836(70)90151-8. [DOI] [PubMed] [Google Scholar]
- Yanagida M. Molecular organization of the shell of T-even bacteriophage head. II. Arrangement of subunits in the head shell of giant phages. J Mol Biol. 1977 Feb 5;109(4):515–537. doi: 10.1016/s0022-2836(77)80089-2. [DOI] [PubMed] [Google Scholar]