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Activation of distant replication origins in vivo by DNA looping as revealed by a novel mutant form of an initiator protein defective in cooperativity at a distance.

1992; Springer Nature; Volume: 11; Issue: 3 Linguagem: Inglês

10.1002/j.1460-2075.1992.tb05161.x

1460-2075

Alexander Miron, Sarmistha Mukherjee, Deepak Bastia,

Advanced biosensing and bioanalysis techniques

Research Article1 March 1992free access Activation of distant replication origins in vivo by DNA looping as revealed by a novel mutant form of an initiator protein defective in cooperativity at a distance. A. Miron A. Miron Department of Microbiology and Immunology, Duke University Medical Center, Durham, NC 27710. Search for more papers by this author S. Mukherjee S. Mukherjee Department of Microbiology and Immunology, Duke University Medical Center, Durham, NC 27710. Search for more papers by this author D. Bastia D. Bastia Department of Microbiology and Immunology, Duke University Medical Center, Durham, NC 27710. Search for more papers by this author A. Miron A. Miron Department of Microbiology and Immunology, Duke University Medical Center, Durham, NC 27710. Search for more papers by this author S. Mukherjee S. Mukherjee Department of Microbiology and Immunology, Duke University Medical Center, Durham, NC 27710. Search for more papers by this author D. Bastia D. Bastia Department of Microbiology and Immunology, Duke University Medical Center, Durham, NC 27710. Search for more papers by this author Author Information A. Miron1, S. Mukherjee1 and D. Bastia1 1Department of Microbiology and Immunology, Duke University Medical Center, Durham, NC 27710. The EMBO Journal (1992)11:1205-1216https://doi.org/10.1002/j.1460-2075.1992.tb05161.x Correction(s) for this article Corrigendum01 May 1992 PDFDownload PDF of article text and main figures. ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InMendeleyWechatReddit Figures & Info We have isolated mutants of the pi initiator protein of the plasmid R6K that are defective in DNA looping in vitro but retain their normal DNA binding affinity for the primary binding sites (iterons) at the gamma origin/enhancer. One such looping defective mutant called R6 was determined to be a proline to leucine change at position 46 near the N terminus of the pi protein. Using a set of genetic assays that discriminate between the activation of the gamma origin/enhancer from those of the distantly located alpha and beta origins, we show that the looping defective initiator protein fails to activate the alpha and beta origins but derepresses initiation from the normally silent gamma origin in vivo. The results conclusively prove that DNA looping is required to activate distant replication origins located at distances of up to 3 kb from the replication enhancer. Previous ArticleNext Article Volume 11Issue 31 March 1992In this issue RelatedDetailsLoading ...