Degree Type

Dissertation

Date of Award

1984

Degree Name

Doctor of Philosophy

Department

Microbiology

Major

Molecular, Cellular, and Developmental Biology

Abstract

The mutations mit-376 and ngr-374 are described which effect genetic recombination and the apurinic/apyrimidinic (AP) endonuclease, respectively, in Staphylococcus aureus NCTC 8325. The mit-376 mutation was isolated from the Rec('-) mutant RN81. When transformed to other strains of S. aureus, this mutation caused sensitivity to DNA alkylating agents, mitomycin C, and UV irradiation. In addition, mit-376 caused a marked reduction in genetic recombination, the severity of which was related to the prophage content of the recipients. The ngr-374 mutation was also isolated from RN981 and caused an increase in sensitivity to DNA alkylating agents, nitrous acid, and UV irradiation. Bioassays for AP endonuclease activity showed that strains carrying ngr-374 have reduced levels of this endonuclease. Furthermore, the UV sensitivity of ngr-372-carrying strains suggests that S. aureus has an AP endonuclease-dependent DNA repair mechanism for UV-generated lesions. By protoplast fusion analysis and genetic transformations the chromosomal locations of these mutations were determined. mit-376 was in the linkage group purA102 - nov-142 - mit-376 - hisG15, and ngr-374 was in the linkage group (OMEGA) chr: :Tn551 42 - ngr-374 - thrB106.

DOI

https://doi.org/10.31274/rtd-180813-5858

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Jeffrey Ernest Tam

Language

en

Proquest ID

AAI8514443

File Format

application/pdf

File Size

173 pages

Included in

Microbiology Commons

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