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Updated: May 27, 2026
06:51
Parallel High Throughput Single Molecule Kinetic Assay for Site-Specific DNA Cleavage
Published on: May 6, 2020
DNA targeting and cleavage by an engineered metalloprotein dimer
Siu Wah Wong-Deyrup1, Charulata Prasannan, Cynthia M Dupureur
1Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
Summary
Engineered protein dimers show enhanced calcium binding and DNA cleavage activity. This advancement in artificial metallonuclease design utilizes biologically relevant metal ions for unique functions.
Area of Science:
- Protein Engineering
- Biochemistry
- Molecular Biology
Background:
- Protein dimerization offers structural and functional benefits.
- A previously designed metallohomeodomain protein (C2) binds metal ions and DNA with limited activity.
- EF-hand and homeodomain motifs were combined to create the C2 protein.
Purpose of the Study:
- To enhance the function of the engineered metalloprotein C2.
- To create a dimeric form of the C2 protein (F2) for improved performance.
- To investigate the DNA cleavage activity of the dimeric metalloprotein.
Main Methods:
- Fluorescence spectroscopy was used to assay calcium binding.
- Gel shift selection experiments determined DNA sequence specificity.
- Plasmid DNA cleavage assays were performed.
Main Results:
- The dimeric F2 protein exhibited 25-fold higher calcium (Ca(II)) binding affinity per domain compared to the C2 monomer.
- Metallated F2 showed specificity for 5'-TAATTA-3' DNA sequences.
- The Ca(2)F2 complex demonstrated calcium-dependent plasmid DNA cleavage, unlike the monomer.
Conclusions:
- Dimerization significantly enhances the functional properties of the engineered metalloprotein.
- The dimeric metalloprotein F2 represents a novel artificial metallonuclease with Ca(II)-dependent DNA cleavage.
- This work advances the design of artificial metallonucleases using biologically significant metal ions.
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