[Using multiple-fragment amplification combined with Gibson assembly to clone genes with site-directed mutations]

Area of Science:

• Molecular Biology
• Genetic Engineering

Background:

• Site-directed mutagenesis is crucial for protein function studies.
• Conventional methods like overlap extension PCR can be complex and inefficient.

Purpose of the Study:

• To develop a simple and efficient site-directed mutagenesis protocol.
• To utilize Gibson assembly for cloning mutated cyclin-dependent kinase 4 genes.

Main Methods:

• Amplified gene fragments with site mutations using a modified overlap extension PCR strategy.
• Generated a linearized vector with overlapping adaptors via double restriction endonuclease digestion.
• Spliced gene fragments and vector using Gibson assembly in a single isothermal reaction.
• Transformed recombinant plasmids into *Escherichia coli* DH5α and screened clones.

Main Results:

• Achieved 100% accuracy for target mutants among randomly selected clones.
• Demonstrated successful cloning of single and double site mutations.
• Eliminated the need for tedious multiple-round PCR and frequent DNA extraction.

Conclusions:

• The developed Gibson assembly protocol offers a simple, efficient, and accurate method for site-directed mutagenesis.
• This approach circumvents major limitations of overlap extension PCR and rolling circle amplification.
• It provides a robust solution for generating genes with single or multiple mutations.