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Updated: Jul 15, 2026
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CAPRRESI: Chimera Assembly by Plasmid Recovery and Restriction Enzyme Site Insertion
Published on: June 25, 2017
An EcoRI-RsrI chimeric restriction endonuclease retains parental sequence specificity
Tungalag Chuluunbaatar1, Tetiana Ivanenko-Johnston, Mónika Fuxreiter
1Institute of Biochemistry, Biological Research Center of the Hungarian Academy of Sciences, P.O. Box 521, 6701 Szeged, Hungary.
Biochimica Et Biophysica Acta
|April 20, 2007
Summary
Researchers created a hybrid restriction enzyme (EERE) from EcoRI and RsrI, finding it retained DNA cleavage specificity but had altered activity and toxicity. This suggests significant structural and functional similarity between the parent enzymes.
Area of Science:
- Molecular Biology
- Enzymology
- Structural Biology
Background:
- Restriction endonucleases EcoRI and RsrI recognize the same DNA sequence and share 50% amino acid identity.
- Understanding enzyme structure-function relationships is crucial for protein engineering.
Purpose of the Study:
- To investigate the structural and functional similarity between EcoRI and RsrI restriction enzymes.
- To construct and characterize a hybrid endonuclease combining features of EcoRI and RsrI.
Main Methods:
- Construction of a chimeric endonuclease (EERE) by swapping a specific segment between EcoRI and RsrI.
- Biochemical assays to determine endonuclease activity and DNA binding affinity.
- Molecular dynamics simulations and computational modeling to analyze structural changes and hydrogen bonding.
- Assessment of cellular toxicity of the chimeric enzyme.
Main Results:
- The EERE chimera exhibited EcoRI/RsrI-specific endonuclease activity, albeit with 100-fold weaker catalytic activity but higher DNA binding affinity than EcoRI.
- Molecular simulations indicated increased hydrogen bonds in the chimera and minimal structural disruption compared to EcoRI.
- The chimeric endonuclease displayed greater toxicity in unprotected cells than the parental EcoRI mutant, potentially due to impaired substrate recognition-cleavage coupling.
Conclusions:
- The successful creation of the EERE hybrid demonstrates significant structural and functional similarity between EcoRI and RsrI restriction enzymes.
- The altered activity and increased toxicity of the chimera provide insights into the intricate relationship between DNA binding, cleavage, and cellular effects.
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