title: Isolation of a gp20-complex and its role in in vitro assembly of both prohead and core of bacteriophage T4.
abstract: The product of gene 20 (gp20) in bacteriophage T4 forms the proximal vertex of the head. It has been suggested that gp20-rich fractions derived from the proheads can initiate core assembly in vitro and that gp20 plays an important role in prohead and core assembly. However, the gp20 isolated from proheads or overproducing cells harboring gene 20 did not work in vitro, owing to a strong tendency to aggregate. Native gp20 was purified from T4-infected Escherichia coli hdB3-1 cells, since it was shown that gp20 might not associate with membrane in this infection. Isolated gp20 is associated with two other proteins in a gp20-complex, composed of a connector and a neck joined to six fibers. The gp20-complex is also produced in T4 infection of E. coli groEL. Moreover, the complex can efficiently induce prohead and core assembly and is very stable.
authors.affiliation: Department of Microbiology, Biozentrum, University of Basel, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Kato
authors.forename: C
authors.initials: C
authors.lastname: Baschong
mesh_terms: D017122:Bacteriophage T4 / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D002213:Capsid / Q000096:biosynthesis / Q000302:isolation & purification / Q000502:physiology*; D036022:Capsid Proteins; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D018834:Chaperonin 60 / Q000096:biosynthesis; D004926:Escherichia coli / Q000502:physiology / Q000648:ultrastructure / Q000821:virology; D005814:Genes, Viral; D014758:Viral Core Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D015678:Viral Structural Proteins / Q000235:genetics; D014779:Virus Replication
chemical_list: D036022:Capsid Proteins; D018834:Chaperonin 60; D014758:Viral Core Proteins; D015678:Viral Structural Proteins; C061379:gp20 protein, bacteriophage T4