Skip Navigation

This Article
Right arrow Print PDF (4860K)
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 Search for citing articles in:
ISI Web of Science (63)
Right arrowRequest Permissions
Right arrow Commercial Re-use Guidelines
for Open Access NAR Content
Google Scholar
Right arrow Articles by Trask, D. K.
Right arrow Articles by Muller, M. T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Trask, D. K.
Right arrow Articles by Muller, M. T.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Nucleic Acids Research, 1983, Vol. 11, No. 9 2779-2800
© 1983

ENZYMOLOGY

Biochemical characterization of topoisomerase I purified from avian erythrocytes

Douglas K. Trask and Mark Twain Muller

Department of Microbiology, The Ohio State University Columbus, OH 43210, USA

Received October 19, 1982. Revised February 24, 1983. Accepted February 24, 1983.

A type I topoisomerase has been purified from avian erythrocyte nuclei. The most pure fraction contains one major polypeptide of Mr = 105,000 (80% of total) and several minor ones of lower molecular weight. Active forms of the topoisomerase were identified by covalently binding the enzyme to P-DNA, digesting with nuclease and detecting 32-p labeled peptides by sodium dodecyl sulfate polyaorylamide gel electrophoresis. Topoisomerase activity, as measured by the ability to oovalently bind DMA, is associated with the following peptides: Mr = 105, 83, 54 and 30,000. The similar chromatographic properties of the various forms of topoisomerase suggests a common structural Identity as previously proposed for the HeLa topoisomerase I (Liu, L.F. and Miller, K.G. (1981) Proc. Nat 1. Acad. Soi. USA 78, 3487–3191). The avian enzyme is similar to other eucaryotic type I DNA topoisomerases in that it covalently binds double and single stranded DNA forming an enzyme linked to the 3'-phosphoryl end and after binding to single stranded DNA it can transfer the single stranded donor DNA to an acceptor DNA possessing 5'-OH end groups. The binding site size of topoisomerase on DNA has also been determined using micrococoal nuclease to digest unprotected DNA in the native enzyme/DNA complex. The enzyme blocks access to the helix over a span of 25 bp. These findings are discussed in light of the distribution and function of topoisomerase I in chromatin.


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


This article has been cited by other articles:


Home page
 Clin. Cancer Res.Home page
C. Gomez-Manzano, M. M. Alonso, W.K. A. Yung, F. McCormick, D. T. Curiel, F. F. Lang, H. Jiang, B. N. Bekele, X. Zhou, R. Alemany, et al.
Delta-24 Increases the Expression and Activity of Topoisomerase I and Enhances the Antiglioma Effect of Irinotecan
Clin. Cancer Res., January 15, 2006; 12(2): 556 - 562.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
S. C. Kampranis, A. D. Bates, and A. Maxwell
A model for the mechanism of strand passage by DNA gyrase
PNAS, July 20, 1999; 96(15): 8414 - 8419.
[Abstract] [Full Text] [PDF]


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.