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Cleavage properties of site-specific restriction endonucleases
1Merck Institute for Therapeutic Research, Rahway, New Jersey 07065.
Gene Amplification and Analysis
|January 1, 1981
Summary
Researchers modified restriction endonuclease activity to generate novel DNA fragments. These fragments, larger or different from standard products, have applications in DNA mapping and genetic engineering.
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- Restriction endonucleases (REs) recognize and cleave specific DNA sequences.
- REs exhibit inherent site preferences influenced by enzyme properties and DNA structure.
- Standard DNA digestion yields predictable fragment sizes.
Purpose of the Study:
- To explore methods for altering restriction endonuclease activity.
- To generate non-standard DNA fragments with potential applications.
- To investigate techniques for modifying DNA cleavage patterns.
Main Methods:
- Utilizing DNA intercalators to amplify RE site preference and induce partial cleavage.
- Employing general protein inhibitors targeting sulfhydryl groups to affect RE activity.
- Modifying DNA bases or preventing DNA methylation to expose new or alter existing restriction sites.
- Relaxing RE specificity to recognize shorter core sequences.
Main Results:
- Achieved production of large and partially cleaved DNA fragments.
- Observed formation of partially digested DNA fragments due to enzyme inhibition.
- Generated DNA fragments with altered sizes and novel cleavage sites.
- Exposed previously inaccessible restriction sites by altering DNA modification or enzyme specificity.
Conclusions:
- Enzyme inhibitors, DNA intercalators, base modifications, and relaxed specificity can yield unique DNA fragments.
- These novel DNA fragments differ from standard restriction digestion products.
- Generated DNA fragments hold potential for DNA mapping, gene cloning, and genetic manipulation.