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Nucleotide exchange and excision technology (NExT) DNA shuffling: a robust method for DNA fragmentation and directed
Kristian M Müller1, Sabine C Stebel, Susanne Knall
1Institut für Biologie III, Universität Freiburg Schänzlestrasse 1, 79104 Freiburg, Germany. kristian@biologie.uni-freiburg.de
Nucleic Acids Research
|August 3, 2005
Summary
This study introduces NExT DNA fragmentation, a novel method for gene library optimization. It uses uracil incorporation and excision for controlled DNA fragmentation, improving gene shuffling efficiency and reducing mutation rates.
Area of Science:
- Molecular Biology
- Biotechnology
- Genetic Engineering
Background:
- DNA shuffling is a key technique for optimizing DNA and protein properties.
- Existing methods for DNA fragmentation can be complex and lack precision.
Purpose of the Study:
- To introduce and validate a novel, rational DNA fragmentation method called NExT (Next-generation enzymatic fragmentation technology).
- To demonstrate the effectiveness of NExT in gene shuffling for property optimization.
Main Methods:
- Gene library amplification via PCR using uridine triphosphate (dUTP) as a thymidine substitute.
- Uracil excision using uracil-DNA-glycosylase followed by backbone cleavage with piperidine.
- Oligonucleotide pool reassembly using a proofreading polymerase and a predictive computer program.
Main Results:
- Adjustable DNA fragmentation size demonstrated using polyacrylamide urea gels.
- A 33% dUTP PCR resulted in shuffled clones with an average fragment size of 86 bases.
- Low mutation rate (0.1%) observed in shuffled chloramphenicol acetyltransferase gene libraries.
Conclusions:
- NExT DNA fragmentation is a rational, reproducible, and easily executed technique superior to existing methods.
- The technique allows for predictable fragmentation patterns and efficient gene shuffling.
- NExT shows potential for application with other nucleotide analogs.