Identification of a potent decatenating enzyme from Escherichia coli Journal Article
| Authors: | DiGate, R. J.; Marians, K. J. |
| Article Title: | Identification of a potent decatenating enzyme from Escherichia coli |
| Abstract: | A topoisomerase has been purified from extracts of a topoisomerase I-deficient strain of Escherichia coli based solely on its ability to segregate pBR322 DNA replication intermediates in vitro. This enzyme rapidly decatenated multiply linked form II:form II DNA dimers to form II DNA, provided that the DNA substrate contained single-stranded regions. Efficient relaxation of negatively supercoiled DNA was observed when reaction mixtures were incubated at 52°C, but not at 30°C (the temperature at which decatenation was readily observed). This topoisomerase was insensitive to the DNA gyrase inhibitor norfloxacin and unaffected by antibody directed against topoisomerase I. Relaxation of a unique plasmid topoisomer revealed that this decatenase changed the linking number of the DNA in steps of one and was therefore a type 1 topoisomerase. The cleavage pattern of a fragment of single-stranded ∅X174 DNA generated by this decatenase was virtually identical to that reported for topoisomerase III, the least characterized topoisomerase present in E. coli. |
| Keywords: | nonhuman; dna replication; dna; escherichia coli; chromosome deletion; isoenzymes; dna topoisomerases, type ii; dna topoisomerase; dna topoisomerases, type i; norfloxacin; priority journal; support, non-u.s. gov't; support, u.s. gov't, p.h.s. |
| Journal Title: | Journal of Biological Chemistry |
| Volume: | 263 |
| Issue: | 26 |
| ISSN: | 0021-9258 |
| Publisher: | American Society for Biochemistry and Molecular Biology |
| Date Published: | 1988-09-15 |
| Start Page: | 13366 |
| End Page: | 13373 |
| Language: | English |
| PUBMED: | 2843517 |
| PROVIDER: | scopus |
| DOI: | 10.1016/S0021-9258(18)37713-5 |
| DOI/URL: | |
| Notes: | Article -- Source: Scopus |
