Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by Akaboshi, E.
Right arrow Articles by Howard-Flanders, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Akaboshi, E.
Right arrow Articles by Howard-Flanders, P.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

J. Biochem, 1990, Vol. 107, No. 5 781-786
© 1990 Japanese Biochemical Society

research-article

DNase I Footprinting Analysis of RecA Protein Polymerized on DNA during Strand Exchange Reaction between a Gapped Circle and a Linear Duplex1

Eiko Akaboshi2 and Paul Howard-Flanders3

Department of Molecular Biophysics and Biochemistry and Department of Therapeutic Radiology, Yale University New Haven, CT 06511, U.S.A.

RecA protein mediates homologous pairing and strand exchange reactions between a circular duplex with a single strand gap and a linear duplex. We have used the DNase I footprinting method to analyze processes involving four strands during these reactions. We asked how the length of DNA protected by RecA protein changes as these reactions proceed. We compared two kinds of gapped DNAs. We found that RecA protein polymerizes rapidly in the forward direction (5‘ to 3’ with respect to the single strand). We found, however, that polymerization in the reverse direction was more prominent with a duplex carrying a longer gap than one carrying a shorter gap. DNase I footprints showing protection by RecA protein were obtained only at limited nuclease concentrations, which in turn depended on the position of the end label and the stage of the strand exchange reaction. As judged by the concentrations of DNase I good for footprinting, the extent of protection by RecA protein was greatest for ( + ) single-stranded DNA at its first binding site, next highest for heteroduplex containing this ( + ) strand, and least for the gapped homoduplex DNA. These differences in DNase I sensitivity can be explained in terms of differences in the accessibility of various strands on the basis of a three-dimensional model for the strand exchange reaction.

1This work was supported by grants GM11014, AM09397, CA39238, and CA26763 to P.H.-F.

2Present address: Institute for Molecular and Cellular Biology, Osaka University, Yamadaoka, Suita, Osaka 565

3Deceased.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.