Divergent Roles of RPA Homologs of the Model Archaeon Halobacterium salinarum in Survival of DNA Damage
1
South Dakota School of Mines and Technology, Biomedical Engineering Program, Rapid City, SD 57701, USA
2
Idaho State University Department of Biological Sciences, Pocatello, ID 83209, USA
3
New Mexico Institute of Mining and Technology, Department of Biology, Socorro, NM 87801, USA
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
‡
Current address: Idaho Veteran’s Research and Education Foundation, 500 W. Fort Street, Boise, ID 83706, USA.
Genes 2018, 9(4), 223; https://doi.org/10.3390/genes9040223
Received: 31 January 2018 / Revised: 8 April 2018 / Accepted: 12 April 2018 / Published: 20 April 2018
(This article belongs to the Special Issue Genetics and Genomics of Extremophiles)
Abstract
The haloarchaea are unusual in possessing genes for multiple homologs to the ubiquitous single-stranded DNA binding protein (SSB or replication protein A, RPA) found in all three domains of life. Halobacterium salinarum contains five homologs: two are eukaryotic in organization, two are prokaryotic and are encoded on the minichromosomes, and one is uniquely euryarchaeal. Radiation-resistant mutants previously isolated show upregulation of one of the eukaryotic-type RPA genes. Here, we have created deletions in the five RPA operons. These deletion mutants were exposed to DNA-damaging conditions: ionizing radiation, UV radiation, and mitomycin C. Deletion of the euryarchaeal homolog, although not lethal as in Haloferax volcanii, causes severe sensitivity to all of these agents. Deletion of the other RPA/SSB homologs imparts a variable sensitivity to these DNA-damaging agents, suggesting that the different RPA homologs have specialized roles depending on the type of genomic insult encountered. View Full-TextKeywords:
haloarchaea; DNA damage; single-stranded DNA binding protein; deletion; ionizing radiation; UV-C; mitomycin C; replication protein A
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Evans, J.J.; Gygli, P.E.; McCaskill, J.; DeVeaux, L.C. Divergent Roles of RPA Homologs of the Model Archaeon Halobacterium salinarum in Survival of DNA Damage. Genes 2018, 9, 223.
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