Transcription generates positively and negatively supercoiled domains in the template

Wu, Heng; Shyy, Shihua; Wang, James C.; Liu, Leroy F.

doi:10.1016/0092-8674(88)90163-8

Cited by 719 publications

(528 citation statements)

References 24 publications

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“…The RNA polymerase complex is too large to follow the individual helical turns of DNA. Its movement along the template strand, therefore, transiently generates domains of positive and negative supercoiling, respectively, ahead and behind the transcriptional bubble [Wu et al, 1988;Rahmouni and Wells, 1992;Moulin et al, 2005]. These topological changes are significantly stabilized if the transcript encodes a membrane protein [Liu and Wang, 1987;Lodge et al, 1989;Lynch and Wang, 1993], because transcription and co-transcriptional translation are coupled with the insertion of nascent polypeptides into the membrane in bacteria, thereby tethering RNA polymerase to the site of protein translocation [Binenbaum et al, 1999].…”

Section: Mechansims Of Nucleoid Organizationmentioning

confidence: 99%

The bacterial nucleoid: A highly organized and dynamic structure

Thanbichler

Wang

Shapiro

2005

J of Cellular Biochemistry

122

101

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Recent advances in bacterial cell biology have revealed unanticipated structural and functional complexity, reminiscent of eukaryotic cells. Particular progress has been made in understanding the structure, replication, and segregation of the bacterial chromosome. It emerged that multiple mechanisms cooperate to establish a dynamic assembly of supercoiled domains, which are stacked in consecutive order to adopt a defined higher-level organization. The position of genetic loci on the chromosome is thereby linearly correlated with their position in the cell. SMC complexes and histone-like proteins continuously remodel the nucleoid to reconcile chromatin compaction with DNA replication and gene regulation. Moreover, active transport processes ensure the efficient segregation of sister chromosomes and the faithful restoration of nucleoid organization while DNA replication and condensation are in progress.

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Section: Mechansims Of Nucleoid Organizationmentioning

confidence: 99%

The bacterial nucleoid: A highly organized and dynamic structure

Thanbichler

Wang

Shapiro

2005

J of Cellular Biochemistry

122

101

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“…Plasmid pC15 [27] was relaxed completely with wheat germ topoisomerase I and purified by phenol extraction and ethanol precipitation prior to use as substrate in the in vitro transcription reactions. The transcription reaction with T3 RNA polymerase were carried out under conditions as described previously [27].…”

Section: In Vitro Transcription Reactionsmentioning

confidence: 99%

“…The transcription reaction with T3 RNA polymerase were carried out under conditions as described previously [27]. DNA topoisomerase I from various sources was added to the reaction as indicated.…”

Section: In Vitro Transcription Reactionsmentioning

confidence: 99%

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Vaccinia virus DNA topoisomerase I preferentially removes positive supercoils from DNA

Fernandez-Beros

Tse‐Dinh

1996

FEBS Letters

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Type I DNA topoisomerases homologous to Escherichia coli topoisomerase I normally only remove negative supercoils from DNA. Topoisomerases I from various eukaryotes share sequence homology and remove both positive and negative supercoils from DNA. Here we report that vaccinia virus topoisomerase I has significant difference in substrate preference from the other homologous type I topoisomerases. Vaccinia virus topoisomerase I shows a definite preference for removal of positive supercoiis. In contrast, topoisomerase I from human, wheat germ and Saccharomyces cerevisiae has little preference between positive and negative supercoils. The vaccinia enzyme may have evolved for functions required for optimal viral growth.

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“…Studies in eukaryotes have shown topoisomerase I to be associated with actively transcribed genes [2,3]: whereas, topoisomerase II is required for DNA replication and for successful traverse of mitosis [4][5][6][7]. Furthermore, studies have suggested a role for topoisomerases in the control of template supercoiling during RNA transcription [8,9]. Through these two fundamentally different mechanisms, DNA topoisomerases modify the topological states of DNA which facilitate various DNA transactions such as DNA replication, RNA transcription, recombination, chromosome condensation/ decondensation, and chromosome segregation.…”

Section: Introductionmentioning

confidence: 99%