Biomaterial Database

Repair of DNA single-strand breaks in X-irradiated yeast. I. Use of the DNA-unwinding method to measure DNA strand breaks. 1985

B Ogorek, and P E Bryant

The DNA-unwinding method developed by Ahnström and his coworkers to measure DNA strand breaks in mammalian cells was used to measure single-strand breaks (SSB) in the DNA of intact yeast cells. DNA unwinding, which took place inside the rigid cell wall of yeast, was investigated as a function of time, radiation dose, and of pH and salt concentration of the alkaline solution. After DNA unwinding had taken place, the cell wall was destroyed by partial enzymatic digestion and sonication in the presence of detergents. Fragments of single- and double-stranded DNA were separated using hydroxylapatite chromatography. In this way the most suitable conditions for DNA unwinding within the cell wall were established. The results show that SSB and double-strand breaks (DSB) give rise to different kinetics of DNA unwinding.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008722	Methods	A series of steps taken in order to conduct research.	Techniques,Methodological Studies,Methodological Study,Procedures,Studies, Methodological,Study, Methodological,Method,Procedure,Technique
D009691	Nucleic Acid Denaturation	Disruption of the secondary structure of nucleic acids by heat, extreme pH or chemical treatment. Double strand DNA is "melted" by dissociation of the non-covalent hydrogen bonds and hydrophobic interactions. Denatured DNA appears to be a single-stranded flexible structure. The effects of denaturation on RNA are similar though less pronounced and largely reversible.	DNA Denaturation,DNA Melting,RNA Denaturation,Acid Denaturation, Nucleic,Denaturation, DNA,Denaturation, Nucleic Acid,Denaturation, RNA,Nucleic Acid Denaturations
D004260	DNA Repair	The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones.	DNA Damage Response
D004271	DNA, Fungal	Deoxyribonucleic acid that makes up the genetic material of fungi.	Fungal DNA
D004277	DNA, Single-Stranded	A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.	Single-Stranded DNA,DNA, Single Stranded,Single Stranded DNA
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker