The purification and properties of the scaffolding protein of bacteriophage lambda.
The Nu3 gene of bacteriophage lambda resides within a cluster of genes that specify structural components of the bacteriophage head. Previous experiments indicate that the Nu3 gene product (gpNu3) is associated with immature proheads but is not detectable in mature proheads or bacteriophage particles, hence its classification as a scaffolding protein. The Nu3 gene has been cloned and overexpressed, and its protein product has been purified. The purified protein is biologically active, as demonstrated by its ability to complement a gpNu3-deficient extract in an in vitro assembly reaction. The sequence of the amino terminus of the protein indicates that translation of Nu3 starts at nucleotide position 5,342 on the standard lambda DNA sequence, yielding a protein with a calculated Mr of 13,396. A combination of gel exclusion chromatography and velocity sedimentation gradient data indicates that gpNu3 possesses an unusually elongated shape.
Ziegelhoffer
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Department of Cellular, Viral, and Molecular Biology, University of Utah Medical Center, Salt Lake City 84132.
Yau
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Chandrasekhar
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GN
Kochan
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Georgopoulos
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Murialdo
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H
D000595:Amino Acid Sequence; D010582:Bacteriophage lambda / Q000737:chemistry* / Q000235:genetics; D001483:Base Sequence; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D010957:Plasmids; D014176:Protein Biosynthesis; D015183:Restriction Mapping; D014758:Viral Core Proteins; D014764:Viral Proteins / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism
D014758:Viral Core Proteins; D014764:Viral Proteins; C068585:protein 22, Enterobacteria phage T4