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DNA2 Encodes a DNA Helicase Essential for Replication of Eukaryotic Chromosomes

Budd, Martin E. and Choe, Won-Chae and Campbell, Judith L. (1995) DNA2 Encodes a DNA Helicase Essential for Replication of Eukaryotic Chromosomes. Journal of Biological Chemistry, 270 (45). pp. 26766-26769. ISSN 0021-9258.

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Although a number of eukaryotic DNA helicases have been identified biochemically and still more have been inferred from the amino acid sequences of the products of cloned genes, none of the cellular helicases or putative helicases has to date been implicated in eukaryotic chromosomal DNA replication. By the same token, numerous eukaryotic replication proteins have been identified, but none of these is a helicase. We have recently identified and characterized a temperature-sensitive yeast mutant, dna2ts, defective in DNA replication, and have cloned the corresponding gene (Kuo, C.-L., Huang, C.-H., and Campbell, J. L.(1983) Proc. Natl. Acad. Sci. U. S. A. 30, 6465-6469; Budd, M. E., and Campbell, J. L.(1995) Proc. Natl. Acad. Sci. U. S. A. 92, 7642-7646). The DNA2 gene is essential and encodes a 172-kDa protein with DNA helicase motifs in its C-terminal half and an N-terminal half with no similarity to any previously described protein (Budd, M. E., and Campbell, J. L. (1995) Proc. Natl. Acad. Sci. U. S. A. 92, 7642-7646). Here we show that the helicase domain is required in vivo and that a 3` to 5` DNA helicase activity specific for forked substrates is intrinsic to the Dna2p. The N terminus is also essential for DNA replication. Thus, the structure of this new helicase is different from all previously characterized replicative helicases, which is consistent with the complex organization of eukaryotic replication forks, where the activities of not one but three essential DNA polymerases must be coordinated.

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Additional Information:©1995 by The American Society for Biochemistry and Molecular Biology, Inc. (Received for publication, August 16, 1995) This work was supported by the National Institute of General Medical Sciences and the National Science Foundation. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Issue or Number:45
Record Number:CaltechAUTHORS:BUDjbc95
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:3433
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Deposited On:06 Jun 2006
Last Modified:02 Oct 2019 23:03

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