HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wick, K. L. Articles by Matthews, K. S. Search for Related Content PubMed PubMed Citation Articles by Wick, K. L. Articles by Matthews, K. S. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 266, Issue 10, 6106-6112, Apr, 1991

Interactions between lac repressor protein and site-specific bromodeoxyuridine-substituted operator DNA. Ultraviolet footprinting and protein-DNA cross-link formation

KL Wick and KS Matthews
Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251.

Specific contacts between the lac repressor and operator have been explored using 5-bromodeoxyuridine-substituted DNA. Substitution of BrdU for single thymidine positions in a synthetic 40-base pair operator provides substrate for ultraviolet irradiation; upon irradiation, strand scission occurs at the BrdU residues. When bound, lac repressor protein provides protection against UV-induced breakage depending on the nature of the sites and type of interaction. We have confirmed 13 unique sites of inducer-sensitive protection along the operator sequence using this method compared to complete substitution with BrdU; differences were observed at two positions for singly substituted versus completely substituted DNAs (Ogata, R., and Gilbert, W. (1977) Proc. Natl. Acad. Sci. U.S.A. 74, 4973-4976). The ability of these photosensitive DNAs to form short range cross-links to bound protein has been used to determine the efficiency with which cross- linked protein-DNA complexes are generated at each individual site of BrdU substitution. Five sites of high efficiency cross-linking to the repressor protein have been identified. At one site, cross-linking without protection from strand scission was observed; this result suggests an unusual mechanism of strand scission and/or cross-linking at this site. Comparison of the UV protection results and the cross- linking data show that these processes provide complementary tools for identifying and analyzing individual protein-DNA contacts.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. Willis, B. Hicke, O. Uhlenbeck, T. Cech, and T. Koch Photocrosslinking of 5-iodouracil-substituted RNA and DNA to proteins Science, November 19, 1993; 262(5137): 1255 - 1257. [Abstract] [PDF]