An Additional Function for Bacteriophage λ rex: The rexB Product Prevents Degradation of the λ O Protein

• Published in: Proceedings of the National Academy of Sciences - PNAS 1991-06, Vol.88 (11), p.4996-5000
• Main Authors: Schoulaker-Schwarz, Rachel, Dekel-Gorodetsky, Lea, Engelberg-Kulka, Hanna
• Format: Article
• Language: English
• Subjects: Antibodies; Bacteriophage lambda - genetics; Bacteriophage lambda - metabolism; Bacteriophages; Biological and medical sciences; Cloning, Molecular; Escherichia coli - genetics; Escherichia coli - metabolism; Fundamental and applied biological sciences. Psychology; Gene expression; Gene expression regulation; Genes; Genetic mutation; Kinetics; Molecular and cellular biology; Molecular genetics; Nonsense mutation; Nucleotides; Operon; Plasmids; Proteins; Restriction Mapping; Viral Proteins - biosynthesis; Viral Proteins - genetics; Viral Proteins - metabolism; Virology
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.88.11.4996

The rex operon of bacteriophage λ excludes the development of several unrelated bacteriophages. Here we present an additional λ rexB function: it prevents degradation of the short-lived protein λ O known to be involved in λ DNA replication. We have shown that it is the product of rexB that is responsible for the stabilization of λ O: when a nonsense mutation is present in rexB, λ O protein is labile; suppression of the mutation by the corresponding nonsense suppressor causes partial restabilization of λ O. λ rexB also stabilizes λ O in trans. We discuss our results in relation to the function of rexB in λ DNA replication and its role in the protein degradation pathways of bacteriophage λ.