Nucleic acid evolution and minimization by nonhomologous random recombination

Area of Science:

• Molecular Biology
• Biotechnology
• Genetics

Background:

• DNA aptamers are crucial for molecular recognition.
• Existing methods for aptamer evolution have limitations in efficiency and functional region identification.

Purpose of the Study:

• To introduce and evaluate nonhomologous random recombination (NRR) as a method for exploring nucleic acid sequence space.
• To compare the efficacy of NRR with error-prone PCR for evolving high-affinity DNA aptamers.
• To assess NRR's ability to facilitate the identification of functional DNA sequences.

Main Methods:

• Development of a novel nonhomologous random recombination (NRR) technique for DNA fragment recombination.
• Comparative evolution of DNA aptamers targeting streptavidin using NRR and error-prone PCR.
• Systematic evolution of ligands by exponential enrichment (SELEX) as a benchmark.

Main Results:

• NRR evolved DNA aptamers with 15- to 20-fold higher affinity than those evolved by error-prone PCR.
• NRR-evolved aptamers showed 27- or 46-fold higher affinities compared to parental sequences from SELEX.
• NRR facilitated the identification of a specific 40-base functional DNA sequence crucial for streptavidin binding.

Conclusions:

• Nonhomologous random recombination (NRR) offers a powerful and efficient approach for nucleic acid evolution.
• NRR surpasses existing methods like error-prone PCR and SELEX in generating high-affinity aptamers.
• NRR simplifies the identification of structure-activity relationships and functional elements within evolved nucleic acid sequences.