Self-replication of DNA by its encoded proteins in liposome-based synthetic cells

TLDR

Replication of DNA-encoded information and its conversion into functional proteins are universal properties of life. The authors aim to construct a synthetic minimal cell by implementing the Φ29 virus DNA replication machinery in a cell‑free gene expression system. They use a cell‑free system to express Φ29 proteins that drive amplification of a linear DNA template. The replicated DNA can serve as a functional template for gene expression, forming an autocatalytic replication cycle that can be compartmentalized inside phospholipid vesicles, providing a chassis for evolving functions in a prospective synthetic cell.

Abstract

Replication of DNA-encoded information and its conversion into functional proteins are universal properties of life. In an effort toward the construction of a synthetic minimal cell, we implement here the DNA replication machinery of the Φ29 virus in a cell-free gene expression system. Amplification of a linear DNA template by self-encoded, de novo synthesized Φ29 proteins is demonstrated. Complete information transfer is confirmed as the copied DNA can serve as a functional template for gene expression, which can be seen as an autocatalytic DNA replication cycle. These results show how the central dogma of molecular biology can be reconstituted and form a cycle in vitro. Finally, coupled DNA replication and gene expression is compartmentalized inside phospholipid vesicles providing the chassis for evolving functions in a prospective synthetic cell relying on the extant biology.