Functional cooperation between exonucleases and endonucleases: basis for the evolution of restriction enzymes

Raghavendra, Nidhanapathi K and Rao, Desirazu N (2003) Functional cooperation between exonucleases and endonucleases: basis for the evolution of restriction enzymes. In: Nucleic Acids Research, 31 (7). pp. 1888-1896.

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Abstract

Many types of restriction enzymes cleave DNA away from their recognition site. Using the type III restriction enzyme, EcoP151, which cleaves DNA 25-27 bp away from its recognition site, we provide evidence to show that an intact recognition site on the cleaved DNA sequesters the restriction enzyme and decreases the effective concentration of the enzyme. EcoP151 restriction enzyme is shown here to perform only a single round of DNA cleavage. Significantly, we show that an exonuclease activity is essential for EcoP151 restriction enzyme to perform multiple rounds of DNA cleavage. This observation may hold true for all restriction enzymes cleaving DNA sufficiently far away from their recognition site. Our results highlight the importance of functional cooperation in the modulation of enzyme activity. Based on results presented here and other data on well-characterised restriction enzymes, a functional evolutionary hierarchy of restriction enzymes is discussed.

Item Type:	Journal Article
Publication:	Nucleic Acids Research
Publisher:	Oxford University Press
Additional Information:	Copyright of this article belongs to Oxford University Press.
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	20 Sep 2007
Last Modified:	19 Sep 2010 04:39
URI:	http://eprints.iisc.ac.in/id/eprint/11851

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