SLESAREV, AI and ZAITZEV, DA and KOPYLOV, VM and STETTER, KO and KOZYAVKIN, SA (1991) DNA TOPOISOMERASE-III FROM EXTREMELY THERMOPHILIC ARCHAEBACTERIA - ATP-INDEPENDENT TYPE-I TOPOISOMERASE FROM DESULFUROCOCCUS-AMYLOLYTICUS DRIVES EXTENSIVE UNWINDING OF CLOSED CIRCULAR DNA AT HIGH-TEMPERATURE. JOURNAL OF BIOLOGICAL CHEMISTRY, 266 (19). pp. 12321-12328. ISSN 0021-9258,
Full text not available from this repository.Abstract
A second type I topoisomerase was purified from the extremely thermophilic archaebacterium Desulfurococcus amylolyticus. In contrast to the previously described reverse gyrase from this organism, the novel enzyme designated as Dam topoisomerase III is an ATP-independent relaxing topoisomerase. It is a monomer with M(r) 108,000, as determined by electrophoresis under denaturing conditions and by size exclusion chromatography. Dam topoisomerase III, like other bacterial type I topoisomerases, absolutely requires Mg2+ for activity and is specific for single-stranded DNA. At 60-80-degrees-C, it relaxes negatively but not positively supercoiled DNA and is inhibited by single-stranded M13 DNA. At 95-degrees-C, the enzyme unwinds both positively and negatively supercoiled substrates and produces extensively unwound form I* and I** DNA. The peculiarities of DNA topoisomerization at high temperatures are discussed.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | RECA PROTEIN-BINDING; ESCHERICHIA-COLI; REVERSE GYRASE; DUPLEX DNA; SUPERHELICAL DNA; PBR322 DNA; INVITRO; RECOMBINATION; SULFOLOBUS; CLEAVAGE; |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:46 |
| URI: | https://pred.uni-regensburg.de/id/eprint/54950 |
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