Journal of Molecular Biology
Volume 117, Issue 2, 5 December 1977, Pages 521-524
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Letter to the editor
Primary structure of internal peptide VII of T-even bacteriophages

https://doi.org/10.1016/0022-2836(77)90141-3Get rights and content

Abstract

As first shown by Hershey (1955,1957), osmotic rupture of the head of bacteriophage T2 releases, together with the DNA, an acid-insoluble protein fraction and an acid-soluble peptide fraction. Subsequent chromatographic analysis of the acid-soludle fraction of bacteriophage T4-infected Escherichia coli resolved two peptides, designated II and VII, corresponding to the peptide fraction of T2 described by Hershey (Eddleman & Champe, 1966). Both peptides were found to be composed largely of acidic residues with only a limited number of other amino acids. The amino acid compositions predicted minimum molecular weights of 3900 (33 residues) and 2700 (23 residues) for peptides II and VII, respectively, consistent with their retardation on Sephadex G25 (Champe & Eddleman, 1967). The formation of these peptides in T4-infected cells parallels the synthesis of late proteins. Pulse-labelling experiments showed, however, that the internal peptides are derived from acid-insoluble precursors, suggesting the probable involvement of proteolytic cleavage in their formation. The role of these peptides, if any, in phage replication is unclear. Eddleman & Champe (1966) suggested that they may be inactive remnants of a core protein whose elimination is required for assembly. Alternatively, Laemmli & Favre (1973) have proposed that the internal peptides may function to facilitate packaging of the DNA in the phage head.

References (20)

  • S.P. Champe et al.
  • H.L. Eddleman et al.

    Virology

    (1966)
  • R. Hayashi et al.

    J. Biol. Chem

    (1973)
  • A.D. Hershey

    Virology

    (1955)
  • A.D. Hershey

    Virology

    (1957)
  • T. Isobe et al.

    J. Mol. Biol

    (1976)
  • U.K. Laemmli et al.

    J. Mol. Biol

    (1973)
  • A. Tsugita et al.

    J. Mol. Biol

    (1975)
  • S. Yokoyama et al.

    Biochim. Biophys. Acta

    (1975)
  • G. Braunitzer et al.

    Hoppe-Seyler's Z. Physiol. Chem

    (1970)
There are more references available in the full text version of this article.

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This work was supported by a Swiss National Science Foundation grant (no. 3.189.73) to one of us (A. T.) and grant no. 3.2130.73 to another author (J. P. v. E.), and by U. S. National Institute of General Medical Sciences grant no. GM-17020 to another (S. P. C.). Carboxypeptidase Y was a gift from Dr R. Hayashi, Kyoto University, and carboxypeptidase P was a gift from Dr E. Ichishima, Tokyo Noko University.

1

Present address: Department of Biochemistry, State University of Groningen, Groningen, Netherlands.

2

Present address: Waksman Institute of Microbiology, Rutgers University, the State University of New Jersey, New Brunswick, N.J., U.S.A.

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