In vitro evolution of terminal protein-containing genomes

In vitro evolution of terminal protein-containing genomes

Centro de Biología Molecular “Severo Ochoa,” Universidad Autónoma, Canto Blanco, 28049 Madrid, Spain

Abstract

A new self-sustained terminal protein-primed DNA amplification system has been used to describe in vitro evolutionary changes affecting maintenance of the genome size of bacteriophage φ29. These changes involve generation and efficient amplification of short palindromic molecules containing an inverted duplication of one of the original DNA ends. A template-switching mechanism is proposed to account for the appearance of these molecules. After their formation, they would replicate by means of hairpin intermediates. Relevant kinetic information about this DNA replication system has been obtained from the competition between the input full-length φ29 DNA and its derived truncated versions. The physiological relevance of these molecules and the mechanisms to control their formation are discussed.

Footnotes

↵ † Present address: The Markey Center for Molecular Genetics, University of Vermont, Stafford Hall, Burlington, VT 05405-0068.
↵ ‡ To whom reprint requests should be addressed. e-mail: msalas{at}mvax.cbm.uam.es.
Charles C. Richardson, Harvard Medical School, Boston, MA
ABBREVIATIONS:

TP,

terminal protein;

dsDNA,

double-stranded DNA;

DBP,

dsDNA-binding protein;

ssDNA,

single-stranded DNA;

SSB,

ssDNA-binding protein