## Abstract Data are presented on a triplex type with two parallel homologous strands for which triplex formation is almost as strong as duplex formation at least for some sequences and even at pH 7 and 0.2β M NaCl. The evidence mainly rests upon comparing thermodynamic properties of similar systems
The recognition of mismatched base pairs in DNA by DNase I from Ustilago maydis
β Scribed by Pukkila, Patricia J.
- Publisher
- Springer
- Year
- 1978
- Tongue
- English
- Weight
- 511 KB
- Volume
- 161
- Category
- Article
- ISSN
- 0026-8925
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β¦ Synopsis
The activity of Ustilago maydis DNase I, an enzyme implicated in genetic recombination, on DNA substrates containing unpaired or mismatched bases, was examined. The enzyme nicked supercoiled PM-2 molecules, converting these to relaxed circular and linear molecules. Discrete double stranded linear fragments smaller than unit length were also observed after digestion at high enzyme concentration. Heteroduplex molecules were constructed using phi80 bacteriophage derivatives which contained single base substitutions within the E. coli tRNA1tyr gene. Single and double stranded nicking at or near the single mismatched site was observed with three out of the five pairs of heteroduplexes.
π SIMILAR VOLUMES
The expedient of preparing homologous DNA samples substituted with inosine for guanosine residues, 2,6-diaminopurine (DAP) for adenine residues, or both, has been used to investigate the role of the purine 2-amino group in determining the preferred binding sites for the drugs berenil [1,3-bis(4-phen