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Updated: Jul 11, 2026
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Generation of Genome-wide Chromatin Conformation Capture Libraries from Tightly Staged Early Drosophila Embryos
Published on: October 3, 2018
Creating multiple-crossover DNA libraries independent of sequence identity
S Lutz1, M Ostermeier, G L Moore
1Department of Chemical Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2694, USA.
Summary
We developed SCRATCHY, a novel protein engineering method combining incremental truncation and DNA shuffling for creating hybrid enzymes independent of sequence identity. This approach successfully generated functional enzymes with multiple gene crossovers.
Area of Science:
- Protein engineering
- Synthetic biology
- Molecular biology
Background:
- Combinatorial protein engineering is crucial for developing novel enzymes with enhanced functions.
- Existing methods often rely on sequence homology, limiting their applicability.
- There is a need for sequence-identity-independent gene recombination techniques.
Purpose of the Study:
- To develop and validate a novel methodology, SCRATCHY, for combinatorial protein engineering.
- To enable the creation of hybrid enzymes through gene recombination irrespective of sequence identity.
- To model the effects of fragmentation and sequence identity on recombination outcomes.
Main Methods:
- Developed SCRATCHY, integrating incremental truncation for gene fusion and DNA shuffling for increased crossovers.
- Created SCRATCHY libraries using glycinamide-ribonucleotide formyltransferase (GART) genes from E. coli and human.
- Employed an in silico modeling framework (eSCRATCHY) to analyze crossover statistics.
- Performed in vivo selection in an auxotrophic E. coli host.
Main Results:
- Successfully generated combinatorial libraries of hybrid enzymes using SCRATCHY.
- Experimental findings for crossover numbers were in good agreement with eSCRATCHY modeling predictions.
- Identified functional hybrid enzymes containing multiple crossovers through in vivo selection.
- Demonstrated the ability to engineer proteins independent of sequence identity.
Conclusions:
- SCRATCHY is an effective methodology for combinatorial protein engineering, independent of sequence identity.
- The eSCRATCHY model provides valuable insights into recombination dynamics and aids in library design.
- The approach facilitates the discovery of functional hybrid enzymes with desired properties.
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