The presence of two mitochondrial DNA topoisomerases in human acute leukemia cells.

Abstract

We have undertaken a study of DNA topoisomerases in mitochondria from human acute leukemia cells. Two activities have been detected in these organelles. One of the enzymes is presumably a type II topoisomerase, i.e., in ATP-dependent reactions it can catenate closed circular plasmid DNA, and decatenate closed circular kinetoplast DNA. A second topoisomerase is presumably a type I enzyme since, it can relax positive as well as negative supercoils in an ATP-independent reaction, it is unable to catenate plasmid DNA or decatenate kinetoplast DNA, and it is inhibited, rather than stimulated, by ATP.

• Authors: F J Castora, G M Lazarus, D Kunes
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 130 Issue 2 Pg. 854-66 (Jul 31 1985) ISSN: 0006-291X [Print] United States
• PMID: 2992488 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Circular
• DNA, Mitochondrial
• Isoenzymes
• Sodium Dodecyl Sulfate
• Adenosine Triphosphate
• DNA Polymerase I
• DNA Polymerase II
• Endopeptidases
• Endopeptidase K
• DNA Topoisomerases, Type I

Topics

• Acute Disease
• Adenosine Triphosphate (pharmacology)
• Animals
• Crithidia
• DNA Polymerase I (metabolism)
• DNA Polymerase II (metabolism)
• DNA Topoisomerases, Type I (metabolism)
• DNA, Circular (analysis)
• DNA, Mitochondrial (metabolism)
• Electrophoresis, Agar Gel
• Endopeptidase K
• Endopeptidases (metabolism)
• Humans
• Isoenzymes (analysis)
• Leukemia, Lymphoid (enzymology, genetics)
• Microscopy, Electron
• Molecular Weight
• Plasmids
• Sodium Dodecyl Sulfate (pharmacology)
• Xenopus