TY  - JOUR
A1  - Rose, Kathleen M.
A1  - Szopa, Jan
A1  - Han, Fu-Sheng
A1  - Cheng, Yung-Chi
A1  - Richter, Arndt
A1  - Scheer, Ulrich
T1  - Association of DNA topoisomerase I and RNA polymerase I: A possible role for topoisomerase I in ribosomal gene transcription
N2  - RNA polymerase I preparations purified from a rat hepatoma contained DNA topoisomerase activity. The DNA topoisomerase associated with the polymerase had an Mr of 110000, required Mg2+ but not ATP, and was recognized by anti-topoisomerase I antibodies. When added to RNA polymerase I preparations containing topoisomerase activity, anti-topoisomerase I antibodies were able to inhibit the DNA relaxing activity of the preparation as well as RNA synthesis in vitro. RNA polymerase II prepared by analogous procedures did not contain topoisomerase activity and was not recognized by the antibodies. The topoisomerase I: polymerase I complex was reversibly dissociated by column chromatography on Sephacryl S200 in the presence of 0.25 M (NH4hS04. Topoisomerase I was immunolocalized in the transcriptionally active ribosomal gene complex containing RNA polymerase I in situ. These data indicate that topoisomerase I and RNA polymerase I are tightly complexed both in vivo and in vitro, and suggest a role for DNA topoisomerase I in the transcription of ribosomal genes.
Y1  - 1988
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/3203
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-33901
ER  -