1. A point mutation in the Nul gene of bacteriophage lambda facilitates phage growth in Escherichia coli with himA and gyrB mutations.
- Author
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Granston AE, Alessi DM, Eades LJ, and Friedman DI
- Subjects
- Bacteriophage lambda enzymology, Bacteriophage lambda growth & development, DNA Topoisomerases, Type II genetics, Genetic Complementation Test, Bacteriophage lambda genetics, Endodeoxyribonucleases genetics, Escherichia coli genetics, Genes, Genes, Viral, Mutation
- Abstract
A mutant of lambda was isolated that grows in the Escherichia coli himA delta/gyrB-him320(Ts) double mutant at 42 degrees C; conditions which are non-permissive for wild-type lambda growth. The responsible mutation, ohm1, alters the 40th codon of the Nul reading frame. The Nul and A gene products comprise the terminase protein which cleaves concatameric DNA into unit-length phage genomes during DNA packaging. The Nul-ohm1 gene product acts in trans to support lambda growth in the double himA/gyrB mutant, and lambda cos154 growth in the single himA mutant. The observation that an alteration in Nul suppresses the inhibition of growth in the double himA/gyrB mutant implicates DNA gyrase, as well as integration host factor, in the DNA:protein interactions that occur at the initiation of packaging.
- Published
- 1988
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