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Figure 3 | BMC Biochemistry

Figure 3

From: Analysis of DNA relaxation and cleavage activities of recombinant Mycobacterium tuberculosis DNA topoisomerase I from a new expression and purification protocol

Figure 3

Relaxation of negatively supercoiled DNA to determine unit activity. A. 500 ng of negatively supercoiled plasmid DNA was subjected to relaxation as per the conditions in "materials and methods" with the indicated amount of EcTOP and MtTOP. B. DNA relaxation by different amounts of EcTOP and MtTOP was quantitated as percent relaxation for comparison. The percent relaxation was determined by dividing the distance between the negatively supercoiled band (SC); and the weighted center of the partially relaxed band (PR); by the distance between the supercoiled band (SC); and the fully relaxed band (FR). In simple terms, percent relaxation = (SC-PR)/(SC-FR) [18]. The percent relaxation values reported are averages of at least three independent experiments. Error bars denote the standard error of mean.

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BMC Biochemistry

ISSN: 1471-2091

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