Studies of DNA repair and mutagenesis in Escherichia coli and Bacillus subtilis

All organisms face constant challenges to the integrity of their genomes, from environmental agents such as ultraviolet light (UV) to errors generated by their own DNA polymerases. To deal with these challenges, all organisms possess a range of DNA repair and damage tolerance systems. In bacteria, there exists an inducible response to DNA damage termed the SOS response, in which damage induces the expression of greater than forty genes involved in repair. Mismatch repair (MMR) is a system by which the cell is able to avoid mutations by correcting DNA replication errors. Working with living Bacillus subtilis cells, the studies described here have found that MutS and MutL, the key proteins of MMR, form discrete foci in response to mismatches. These MMR foci are the active sites of repair, and appear to assemble near the DNA polymerase at mismatched base-pairs. This is consistent with a model in which the newly-synthesized DNA strand containing the error is discriminated from the parental strand via interactions between MMR proteins and the replisome.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Biology.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Smith, Bradley Theodore

Advisor dc:contributor.advisor

• Graham C. Walker.

• Biology.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8184

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8184