Efficient replication bypass of size-expanded DNA base pairs in bacterial cells

Area of Science:

• Synthetic biology
• Molecular biology
• Genetics

Background:

• Standard DNA bases (A, T, C, G) limit sequence encoding.
• Expanding DNA base size offers potential for novel genetic information storage.

Purpose of the Study:

• To investigate the in vitro and in vivo replication fidelity of size-expanded DNA bases (xDNA).
• To determine if xDNA can be incorporated into natural DNA sequences and replicated accurately.

Main Methods:

• In vitro nucleotide incorporation assays using DNA polymerase.
• In vivo replication studies in Escherichia coli (E. coli) with engineered xDNA bases.

Main Results:

• DNA polymerase demonstrated correct nucleotide incorporation opposite xDNA bases in vitro.
• Two specific xDNA bases (xA and xC) were shown to pair correctly during replication in E. coli.
• xDNA bases successfully encoded natural DNA sequences during replication.

Conclusions:

• Size-expanded DNA bases (xDNA) are compatible with DNA replication machinery.
• xDNA holds potential for expanding the genetic alphabet and enabling novel biotechnological applications.