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Site-Specific Cleavage of Left-Handed DNA in pBR322 by Lambda-tris(diphenylphenanthroline)cobalt(III)

Barton, Jacqueline K. and Raphael, Adrienne L. (1985) Site-Specific Cleavage of Left-Handed DNA in pBR322 by Lambda-tris(diphenylphenanthroline)cobalt(III). Proceedings of the National Academy of Sciences of the United States of America, 82 (19). pp. 6460-6464. ISSN 0027-8424. PMCID PMC390736.

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The chiral complex tris(4,7-diphenyl-1,10-phenanthroline)cobalt(III), Lambda -Co(DiP)33+, binds to and, with photoactivation, cleaves left-handed DNA helices, thereby providing a unique molecular probe for local DNA conformation. We have mapped the specific left-handed sites where Lambda -Co(DiP)33+ cleaves in the plasmids pBR322 and pLP32, which is the derivative of pBR322 containing a Z-form d(C-G)16 insert. For pLP32, a primary cleavage is at the insert; for native pBR322, cleavage occurs at four discrete sites: 1.45, 2.3, 3.3, and 4.2 kilobase pairs. These sites correspond to segments of alternating purine-pyrimidines. Moreover, these positions map to the ends of the three distinct coding regions in pBR322: the tetracycline-resistance gene, the origin of replication, and either end of the ampicillin-resistance (ß -lactamase) gene. The locations of these left-handed segments suggest to us that Z-DNA might serve as a conformational punctuation mark to demarcate the ends of genes.

Item Type:Article
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Barton, Jacqueline K.0000-0001-9883-1600
Additional Information:© 1985 National Academy of Sciences. Communicated by Gilbert Stork, June 3, 1985. This work has been supported by the National Institutes of Health (GM33309) and the National Science Foundation (CHE-83-51017), which are gratefully acknowledged. J.K.B. is a fellow of the Alfred P. Sloan Foundation. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
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Alfred P. Sloan FoundationUNSPECIFIED
Issue or Number:19
PubMed Central ID:PMC390736
Record Number:CaltechAUTHORS:BARpnas85
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:637
Deposited By: Archive Administrator
Deposited On:08 Sep 2005
Last Modified:02 Oct 2019 22:35

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