Eukaryotic DNA topoisomerase I reaction is topology dependent.
AUTOR(ES)
Camilloni, G
RESUMO
The effects of supercoiling on the topoisomerization reaction by eukaryotic DNA topoisomerases I have been analyzed. The systems used were: DNA topoisomerase I from wheat germ, chicken erythrocyte and calf thymus on a 2.3 kb DNA fragment which encompasses the immunoglobulin kappa-light chain (L kappa) promoter of the mouse plasmacytoma MPC11; S. cerevisiae DNA topoisomerase I on a 2.2 kb DNA fragment from the same organism which encompasses the regulatory and the coding region of the ADH II gene; wheat germ DNA topoisomerase I on the plasmid pUC18. It was found in every system that lack of torsional stress prevents topoisomerization of the substrate. A simple regulatory model of DNA topoisomerase I function, based on topological considerations, is presented.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=338352Documentos Relacionados
- Eukaryotic topoisomerase I-DNA interaction is stabilized by helix curvature.
- Topoisomerase II cleavage of herpes simplex virus type 1 DNA in vivo is replication dependent.
- Resolution of Holliday junctions by eukaryotic DNA topoisomerase I.
- Eukaryotic type I topoisomerase is enriched in the nucleolus and catalytically active on ribosomal DNA.
- Association of eukaryotic DNA topoisomerase I with nucleosomes and chromosomal proteins.