Regulation of Tn5 by the right-repeat proteins: Control at the level of the transposition reaction?

Ralph R. Isberg, Aili L. Lazaar, Michael Syvanen

Research output: Contribution to journalArticlepeer-review

55 Scopus citations


The transposon Tn5 consists of inverted repeats, called IS50R and IS50L, each of which encode two proteins. We show here that the larger protein encoded on IS50R, protein 1, is absolutely required for transposition. Deletion or insertion mutants that fail to make this protein fail to promote gene movement. In addition, this protein acts in cis preferentially. We also show that the smaller protein encoded on IS50R, protein 2, is competent to inhibit transposition of a Tn5 freshly introduced into the cell on a λ phage. In contrast, the proteins from IS50L possess neither of these two activities. By assaying expression of proteins that are hybrids between β-galactosidase and IS50R proteins, we find that the regulation of transposition cannot be due to the inhibitor repressing synthesis of Tn5 proteins. Control experiments, in which we assay synthesis of IS50 proteins synthesized from a λ::IS50R that has been infected into cells carrying the transposition inhibitor, confirm this conclusion.

Original languageEnglish (US)
Pages (from-to)883-892
Number of pages10
Issue number3
StatePublished - 1982
Externally publishedYes

ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology


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