TY - JOUR
T1 - Direct interaction between Escherichia coli RNA polymerase and the zinc ribbon domains of DNA topoisomerase I
AU - Cheng, Bokun
AU - Zhu, Chang Xi
AU - Ji, Chengling
AU - Ahumada, Adriana
AU - Tse-Dinh, Yuk Ching
PY - 2003/8/15
Y1 - 2003/8/15
N2 - Escherichia coli DNA topoisomerase I (encoded by the topa gene) is important for maintaining steady-state DNA supercoiling and has been shown to influence vital cellular processes including transcription. Topoisomerase I activity is also needed to remove hypernegative supercoiling generated on the DNA template by the progressing RNA polymerase complex during transcription elongation. The accumulation of hypernegative supercoiling in the absence of topoisomerase I can lead to R-loop formation by the nascent transcript and template strand, leading to suppression of transcription elongation. Here we show by affinity chromatography and overlay blotting that E. coli DNA topoisomerase I interacts directly with the RNA polymerase complex. The protein-protein interaction involves the β′ subunit of RNA polymerase and the C-terminal domains of E. coli DNA topoisomerase I, which are homologous to the zinc ribbon domains in a number of transcription factors. This direct interaction can bring the topoisomerase I relaxing activity to the site of transcription where its activity is needed. The zinc ribbon C-terminal domains of other type IA topoisomerases, including mammalian topoisomerase III, may also help link the enzyme activities to their physiological functions, potentially including replication, transcription, recombination, and repair.
AB - Escherichia coli DNA topoisomerase I (encoded by the topa gene) is important for maintaining steady-state DNA supercoiling and has been shown to influence vital cellular processes including transcription. Topoisomerase I activity is also needed to remove hypernegative supercoiling generated on the DNA template by the progressing RNA polymerase complex during transcription elongation. The accumulation of hypernegative supercoiling in the absence of topoisomerase I can lead to R-loop formation by the nascent transcript and template strand, leading to suppression of transcription elongation. Here we show by affinity chromatography and overlay blotting that E. coli DNA topoisomerase I interacts directly with the RNA polymerase complex. The protein-protein interaction involves the β′ subunit of RNA polymerase and the C-terminal domains of E. coli DNA topoisomerase I, which are homologous to the zinc ribbon domains in a number of transcription factors. This direct interaction can bring the topoisomerase I relaxing activity to the site of transcription where its activity is needed. The zinc ribbon C-terminal domains of other type IA topoisomerases, including mammalian topoisomerase III, may also help link the enzyme activities to their physiological functions, potentially including replication, transcription, recombination, and repair.
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U2 - 10.1074/jbc.M303403200
DO - 10.1074/jbc.M303403200
M3 - Article
C2 - 12788950
AN - SCOPUS:0042733395
SN - 0021-9258
VL - 278
SP - 30705
EP - 30710
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 33
ER -