Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Formation in vitro of Infective Joint Molecules of λ DNA by T4 Gene-32 Protein

Wilfried Wackernagel and Charles M. Radding
Proceedings of the National Academy of Sciences of the United States of America
Vol. 71, No. 2 (Feb., 1974), pp. 431-435
Stable URL: http://www.jstor.org/stable/62790
Page Count: 5
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Formation in vitro of Infective Joint Molecules of λ  DNA by T4 Gene-32 Protein
Preview not available

Abstract

Half molecules of λ DNA that had been partially digested by λ exonuclease to expose homologous single strands were rejoined by the action of T4 gene-32 protein at 37 degrees in the presence of Mg++. Measurements of infectivity in su- spheroplasts and sedimentation in sucrose demonstrated the formation of sus+ joint molecules from two preparations of sheared λ DNA that carried sus mutations at opposite ends of the genome. The biological activity of joint molecules made by annealing at 75 degrees was diminished by the addition of the gene-32 protein in the absence of Mg++, and largely restored by the subsequent addition of Mg++. The specific infectivity of joint molecules made by gene-32 protein at 37 degrees was similar to that of joint molecules made by annealing at 75 degrees. The experimental system described provides a possible model for simulating early steps in genetic recombination.

Page Thumbnails

  • Thumbnail: Page 
431
    431
  • Thumbnail: Page 
432
    432
  • Thumbnail: Page 
433
    433
  • Thumbnail: Page 
434
    434
  • Thumbnail: Page 
435
    435