Words similar to zd
Example sentences for: zd
How can you use “zd” in a sentence? Here are some example sentences to help you improve your vocabulary:
There are two homologous type IA topoisomerases present in E. coli . Topoisomerase III has potent DNA decatenating activity for resolution of plasmid DNA replication intermediates, but much weaker relaxation activity than topoisomerase I [ 17 ] . To exhibit maximal relaxation activity, topoisomerase III requires high temperature (52°C) along with low magnesium and monovalent ion [ 17 18 ] . In contrast, E. coli topoisomerase I was not active in the in vitro assay for resolution of plasmid DNA replication intermediates [ 19 ] . Removal of the C-terminal 49 amino acids from the 653 amino acid topoisomerase III protein resulted in drastic reduction of catalytic activity [ 20 ] . Fusion of the carboxyl-terminal 312 amino acid residues of E. coli topoisomerase I, which includes the entire ZD domain, onto the 605 N-terminal amino acids of topoisomerase III generated a hybrid topoisomerase that has relaxation activity resembling topoisomerase III along with weak decatenating activity [ 21 ] . Although preferring single-stranded DNA as binding substrate, topoisomerase I had been shown to also bind double-stranded DNA [ 22 ] , but there is no data available to indicate which domain in the enzyme is responsible for this interaction.
ZD domain was found to bind to single-stranded DNA, but not double-stranded DNA, with high affinity.
However, with the same oligonucleotide in a duplex form (Figure 3b), Top67 exhibited much higher affinity (half maximal binding value = 0.07 μM) than the ZD domain (half maximal binding value > 5 μM).
Top67 and the ZD domains at different concentrations were mixed and incubated at 37°C for 10 min before addition to the 0.3 μg of supercoiled plasmid DNA in 20 μl of 10 mM Tris-HCl pH 8.0, 2 mM MgCl 2 , 0.1 mg/ml gelatin.
After cleavage of the DNA gate strand which becomes covalently linked to Tyr319 on Top67 (step 2), protein conformational change involving both Top67 and the ZD domain increases the distance between the covalently bound 5' phosphate and non-covalently bound 3' hydroxyl of the cleaved DNA gate strand while the passing DNA strand (T-strand) is guided through the "gate" via interaction with the ZD domain (step 3) to lead to change in linking number.
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