title: Isolation and characterization of a molecular chaperone, gp57A, of bacteriophage T4.
abstract: A molecular chaperone of bacteriophage T4, gp57A, which facilitates the formation of the long and short tail fibers, was isolated and characterized by peptide analysis, sedimentation equilibrium, and circular dichroism (CD). Sequence analysis confirmed the predicted sequence of 79 amino acids from the nucleotide sequence of the gene with the N-terminal methionine removed. The result led to the conclusion that the apparent smaller molecular weight of 6,000 from Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis than the expected molecular weight of 8,710 was due to its abnormal electrophoretic behavior instead of cleavage or processing of the gene product. Estimation of the secondary structure from far-UV CD indicated a 94% alpha-helix content, which was in accord with the prediction from the primary structure. A sedimentation equilibrium study, on the other hand, revealed that gp57A assumes a tetrameric subunit structure.
authors.affiliation: Department of Life Science, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsui
authors.forename: B
authors.initials: B
authors.lastname: Griniuviené
authors.forename: E
authors.initials: E
authors.lastname: Goldberg
authors.forename: A
authors.initials: A
authors.lastname: Tsugita
authors.forename: N
authors.initials: N
authors.lastname: Tanaka
authors.forename: F
authors.initials: F
authors.lastname: Arisaka
mesh_terms: D000595:Amino Acid Sequence; D017122:Bacteriophage T4 / Q000737:chemistry*; D002499:Centrifugation, Density Gradient; D002942:Circular Dichroism; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D005816:Genetic Complementation Test; D018832:Molecular Chaperones / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010449:Peptide Mapping; D017433:Protein Structure, Secondary; D014764:Viral Proteins
chemical_list: C104876:Gp57A protein, Bacteriophage T4; D018832:Molecular Chaperones; D014764:Viral Proteins