Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 25, 1976 | public
Journal Article

The process of infection with bacteriophage φX174. XXXIX. The structure of a DNA form with restricted binding of intercalating dyes observed during synthesis of φX single-stranded DNA

Abstract

A DNA form with restricted binding of intercalating dyes (propidium iodide or ethidium bromide) has been found in bacteriophage φX-infected cells during the period of single-stranded DNA synthesis. In the electron microscope, this DNA form is seen to be a double-stranded DNA ring with two single-stranded DNA tails protruding from the same portion of the ring; it is composed of a linear φX DNA strand, longer than one φX genome, and a single-stranded ring complementary to φX DNA. Base-pairing of these two tails in partially complementary regions restricts unwinding of the double-stranded DNA ring and consequently intercalation and binding of the dyes. It is postulated that these molecules originate from a previously reported precursor of φX DNA, namely a double-stranded ring with a single-stranded tail, by branch migration.

Additional Information

© 1976 Elsevier Ltd. Received 29 August 1975, Revised 22 December 1975. ThH authors are grateful to Dr Harurni Kasamatsu for performing part of the electroll microscopy, her valuable advice on this technique and useful discussions. We would also like to acknowledge useful discussions with Dr John Lee Compton. This research was supported by a grant from the U.S. Public Health Service, GM13554.

Additional details

Created:
August 19, 2023
Modified:
October 20, 2023