Intradimerically tethered DNA topoisomerase II is catalytically active in DNA transport.
AUTOR(ES)
Lindsley, J E
RESUMO
A covalently cross-linked dimer of yeast DNA topoisomerase II was created by fusing the enzyme with the GCN4 leucine zipper followed by two glycines and a cysteine. Upon oxidation of the chimeric protein, a disulfide bond forms between the two carboxyl termini, covalently and intradimerically cross-linking the two protomers. In addition, all nine of the cysteines naturally occurring in topoisomerase II have been changed to alanines in this construct. This cross-linked, cysteine-less topoisomerase II is catalytically active in DNA duplex passage as indicated by ATP-dependent DNA supercoil relaxation and kinetoplast DNA decatenation assays. However, these experiments do not directly distinguish between a "one-gate" and a "two-gate" mechanism for the enzyme.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=39745Documentos Relacionados
- Eukaryotic type I topoisomerase is enriched in the nucleolus and catalytically active on ribosomal DNA.
- Cellular distribution of mammalian DNA topoisomerase II is determined by its catalytically dispensable C-terminal domain.
- Translocation pathway in the catalysis of active transport.
- Topoisomerase II drives DNA transport by hydrolyzing one ATP
- Active heterodimers are formed from human DNA topoisomerase II alpha and II beta isoforms.