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Volumn 277, Issue 5326, 1997, Pages 690-693

Simplification of DNA topology below equilibrium values by type II topoisomerases

Author keywords

[No Author keywords available]

Indexed keywords

DNA; DNA TOPOISOMERASE (ATP HYDROLYSING);

EID: 0030758268     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.277.5326.690     Document Type: Article
Times cited : (243)

References (29)
  • 1
    • 0003564812 scopus 로고
    • D. Rickwood, Ed. Oxford Univ. Press, New York
    • A. D. Bates and A. Maxwell, in DNA Topology, D. Rickwood, Ed. (Oxford Univ. Press, New York, 1993).
    • (1993) DNA Topology
    • Bates, A.D.1    Maxwell, A.2
  • 7
    • 0027200062 scopus 로고
    • V. V. Rybenkov, N. R. Cozzarelli, A. V. Vologodskii, ibid. 90, 5307 (1993); S. Y. Shaw and J. C. Wang, Science 260, 533 (1993).
    • (1993) Science , vol.260 , pp. 533
    • Shaw, S.Y.1    Wang, J.C.2
  • 13
    • 15444347363 scopus 로고    scopus 로고
    • note
    • 2, 1 mM dithiothreitol, bovine serum albumin (50 μg/ml), 1 mM ATP, and either 80 mM potassium acetate for E. coli topoisosomerases III and IV and bacteriophage T2 topo II or 200 mM potassium acetate for eukaryotic topo II, so that each enzyme was assayed under its optimal ionic conditions. The reactions were carried out at 30°C for 60 min, quenched by adding 20 mM EDTA, 0.5% SDS, and 100 μg/ml proteinase K, and incubated for an additional 60 min at 30°C. Because topo III requires single-stranded regions of DNA for optimal activity, this enzyme was assayed on pAB4 DNA containing a 25-nucleotide-long gap generated by exonuclease III from E. coli.
  • 17
    • 15444357069 scopus 로고    scopus 로고
    • note
    • Alternatively, topoisomerases could bend DNA upon binding or change its persistence length. This, however, would substantially alter the topological equilibrium only if the enzyme binds DNA every persistence length or so, and the effects we observed were for s values <1.
  • 23
    • 15444360330 scopus 로고    scopus 로고
    • note
    • Roca and Wang found that a large fraction of crossovers that were bound by the yeast topo II were enzymatically inactive (19). Moreover, in the decatenation of a supercoiled DNA molecule singly linked to an open circle, the enzyme bound preferentially to a G-segment on the supercoiled DNA but efficiently transported a T-segment from the nicked molecule (21). These results suggest that although topoisomerases bind preferentially to a DNA crossover, the T-segment is not ordinarily one of the two crossing segments.
  • 29
    • 15444352926 scopus 로고    scopus 로고
    • note
    • We thank T. Hsieh for D. melanogaster topo II, K. Marians for E coli topo III, L. Shen for human topo II, J. Wang for Saccharomyces cerevisiae full-length and COOH-terminally truncated topo II, and I. Tinoco, J. Wang, and P. Wolynes for valuable discussions. Supported by NIH grants GM31657 to N.R.C. and GM54215 to A.V.V. and a Howard Hughes Medical Institute Predoctoral Fellowship to C.U.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.