Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4

  title={Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4},
  author={Ulrich K. Laemmli},
Using an improved method of gel electrophoresis, many hitherto unknown proteins have been found in bacteriophage T4 and some of these have been identified with specific gene products. Four major components of the head are cleaved during the process of assembly, apparently after the precursor proteins have assembled into some large intermediate structure. 
Involvement of a bacterial factor in morphogenesis of bacteriophage capsid.
A new bacterial factor has been found necessary for the activity of T4 gene 31, the only catalytic factor in the early stage of phage head formation, to process the assembly of head precursor
Characterization and crystallization of the helicase domain of bacteriophage T7 gene 4 protein
Limited proteolysis of bacteriophage T7 primase/helicase with endoproteinase Glu-C produces several proteolytic fragments, which were prepared and shown to retain helicase activity, which supports a model in which the gene 4 proteins consist of functionally separable domains.
Cleavage of T4-induced proteins during phage morphogenesis: characterization of peptides.
Six peptides extracted from T4 coliphages and from Escherichia coli B cells infected with a wild type and various amber mutants of bacteriophage T4 were fractionated by chromatography on phosphocellulose: three of them were cleaved from proteins synthesized late in infection and related to phage head.
Review Structure and morphogenesis of bacteriophage T4
Bacteriophage T4 is one of the most complex viruses, which consists of a protein shell encapsidating a 172-kbp double-stranded genomic DNA, a 'tail,' and fibers, attached to the distal end of the tail.
Identification of gene products required for in vitro formation of the internal peptides of bacteriophage T4
In vitro formation of both bacteriophage T4 internal peptides (II and VII) from preexisting precursor protein was shown to require the product of T4 gene 21, suggesting that the proteolytic factor is inactivated during normal phage assembly.
Assembly core of bacteriophage T4: an intermediate in head formation.
An unstable assembly core initiates phage T4 head formation. T4 core proteins—P22 and internal proteins—nucleate capsid assembly but have no structural role in the completed capsid.
The Assembly of Bacteriophage Functional Enzymatic Models in Association with E. coli Proteins’ Profiles
The proteomic relationship among phage and bacterium proteins could easily be studied by their protein profi les analysis.


Morphogenesis of bacteriophage T4 in extracts of mutant-infected cells.
  • R. Edgar, W. Wood
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1966
In the experiments reported below, conditional lethal mutants of strain T4D have been exploited to develop an in vitro system in which several of the steps in phage morphogenesis can be demonstrated.