TY - JOUR
T1 - Transcription generates positively and negatively supercoiled domains in the template
AU - Wu, Hai Young
AU - Shyy, Shihua
AU - Wang, James C.
AU - Liu, Leroy F.
N1 - Funding Information:
We thank Mr. Hui Zhang and Dr. Mary-Ann Bjornsti for helpful discussions, and Mr. Yeou-Ping Tsao for technical assistance. This work was supported by National Institutes of Health grants GM27731 (to L. F. L.) and GM24544 (to J. C. W.). Part of this work was conducted while three of the authors were visiting at the Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan. The support of the Academia Sinica and the National Science Council (Republic of China) is gratefully acknowledged. J. C. W. was a Guggenheim fellow for the academic year 1986-87, and L. F. L. is a recipient of an American Cancer Society faculty research award. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked ‘advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
PY - 1988/5/6
Y1 - 1988/5/6
N2 - We show that transcription of a DNA molecule inside a bacterium is accompanied by local and temporal supercoiling of the DNA template: as transcription proceeds, DNA in front of the transcription ensemble becomes positively supercoiled, and DNA behind the ensemble becomes negatively supercoiled. Because bacterial gyrase and topoisomerase I act differently on positively and negatively supercoiled DNA, the formation of twin supercoiled domains during transcription is manifested by a large increase or decrease in the linking number of an intracellular plasmid when bacterial DNA gyrase or topoisomerase I, respectively, is inhibited. Such changes in linking number are strongly dependent on transcription of the plasmid in cis and on the relative orientations of transcription units on the plasmid. These results indicate that the state of supercoiling of bacterial DNA is strongly modulated by transcription, and that DNA topoisomerases are normally involved in the elongation step of transcription.
AB - We show that transcription of a DNA molecule inside a bacterium is accompanied by local and temporal supercoiling of the DNA template: as transcription proceeds, DNA in front of the transcription ensemble becomes positively supercoiled, and DNA behind the ensemble becomes negatively supercoiled. Because bacterial gyrase and topoisomerase I act differently on positively and negatively supercoiled DNA, the formation of twin supercoiled domains during transcription is manifested by a large increase or decrease in the linking number of an intracellular plasmid when bacterial DNA gyrase or topoisomerase I, respectively, is inhibited. Such changes in linking number are strongly dependent on transcription of the plasmid in cis and on the relative orientations of transcription units on the plasmid. These results indicate that the state of supercoiling of bacterial DNA is strongly modulated by transcription, and that DNA topoisomerases are normally involved in the elongation step of transcription.
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U2 - 10.1016/0092-8674(88)90163-8
DO - 10.1016/0092-8674(88)90163-8
M3 - Article
C2 - 2835168
AN - SCOPUS:0024279845
VL - 53
SP - 433
EP - 440
JO - Cell
JF - Cell
SN - 0092-8674
IS - 3
ER -