Mechanism of Mutation in Non-Dividing Cells
Abstract
Stationary-phase mutation is a mutational program that can be induced in non-dividing cells after exposure to environmental stress. We are testing the hypothesis that DNA double-strand breaks (DSBs) activate Lac+ stationary-phase mutation in E. coli. In one model for stationary-phase mutation, recombination-mediated repair of a DSB is suggested to promote mutation by priming error-prone DNA replication. F. plasmid transfer (Tra) proteins are required for stationary-phase reversion of a lac +1 frame shift mutation on the F.. Tra functions induce single-strand nicks on the F., which could lead to DSBs. We are asking whether DSBs introduced specifically near lac on the F. can substitute for Tra functions and activate stationary-phase mutation. To make specific DSBs, we constructed strains that express the S. cerevisiae endonuclease 1-Scel from the E. coli chromosome. We find that introducing specific breaks at sites on either side of lac on a transfer-defective F. causes 50-2000-fold stimulations of Lac+ stationary-phase mutation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2001
- Accession Number
- ADA396563
Entities
People
- Rebecca Ponder
- Susan M Rosenberg
Organizations
- Baylor College of Medicine