Sequence specific interaction of Mycobacterium smegmatis topoisomerase I with duplex DNA

Bhaduri, T and Sikder, D and Nagaraja, V (1998) Sequence specific interaction of Mycobacterium smegmatis topoisomerase I with duplex DNA. In: Nucleic Acids Research, 26 (07). pp. 1668-1674.

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Abstract

We have identified strong topoisomerase sites (STS) for Mycobacteruim smegmatis topoisomerase I in double-stranded DNA context using electrophoretic mobility shift assay of enzyme-DNA covalent complexes; Mg2+, an essential component for DNA relaxation activity of the enzyme, is not required for binding to DNA, The enzyme makes single-stranded nicks, with transient covalent interaction at the 5'-end of the broken DNA strand, a characteristic akin to prokaryotic topoisomerases. More importantly, the enzyme binds to duplex DNA having a preferred site with high affinity, a. property similar to the eukaryotic type I topoisomerases, The preferred cleavage site is mapped on a 65 bp duplex DNA and found to be CG/TCTT. Thus, the enzyme resembles other prokaryotic type I topoisomerases in mechanistics of the reaction, but is similar to eukaryotic enzymes in DNA recognition properties.

Item Type:	Journal Article
Additional Information:	Copyright of this article belongs to Oxford University Press.
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	17 Dec 2009 08:16
Last Modified:	19 Sep 2010 05:27
URI:	http://eprints.iisc.ernet.in/id/eprint/19225

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