A mutant of Escherichia coli hyper-resistant to a number of DNA damaging agents: location of the mutational site

Journal of Photochemistry and Photobiology. B, Biology
S I Ahmad

Abstract

A mutant of Escherichia coli, isolated as hyper-resistant to UVC, is found to be hyper-resistant to UVA, H2O2, low concentrations of nalidixic acid, novobiocin, UVA plus H2O2 and UVA plus 8-methoxypsoralen. A mutational site (uvh) conferring the hyper-resistance phenotype to UVC, and presumably to other DNA damaging agents, has been mapped at the 89.9 min region on the chromosome. Complementation analysis with an F-prime uvh+/uvh- diploid strain showed that the uvh+ allele is dominant over uvh- in trans. Studies with a variety of plasmids, carrying various LexA regions, introduced into the UV hyper-resistant strain show that mutation at the uvh locus may be responsible for derepression of the SOS inducible repair system. Based on the results, it is suggested that uvh is a part of the SOS inducible system. A plausible explanation for the hyper-resistance phenotypes for various DNA damaging agents and a model for the genetic control of a second set of putative SOS regulons are presented.

References

Jan 1, 1977·Proceedings of the National Academy of Sciences of the United States of America·D W Mount
May 15, 1992·Proceedings of the National Academy of Sciences of the United States of America·A T Thliveris, D W Mount
May 1, 1989·Proceedings of the National Academy of Sciences of the United States of America·M F ChristmanB N Ames
Jan 1, 1989·Advances in Genetics·A Eisenstark
Dec 1, 1972·Bacteriological Reviews·B J Bachmann
Aug 1, 1993·Mutation Research·M Altshuler
Aug 1, 1993·Journal of Bacteriology·J W Little

❮ Previous
Next ❯

Citations

Sep 2, 1999·Trends in Microbiology·S I Ahmad
Jul 29, 1998·Journal of Photochemistry and Photobiology. B, Biology·G B ZavilgelskyS I Ahmad
Mar 30, 2000·Journal of Photochemistry and Photobiology. B, Biology·L M AsadN R Asad
Jan 19, 1999·Annual Review of Microbiology·S I AhmadA Eisenstark
Sep 8, 1998·Microbiology and Molecular Biology Reviews : MMBR·M K Berlyn

❮ Previous
Next ❯

Related Concepts

Related Feeds

Allergy & Infectious Diseases (ASM)

Allergies result from the hyperreactivity of the immune system to some environmental substance and can be life-threatening. Infectious diseases are caused by organisms including bacteria, viruses, fungi and parasites. They can be transmitted different ways, such as person-to-person. Here is the latest research on allergy and infectious diseases.

Antimicrobial Resistance (ASM)

Antimicrobial resistance poses a significant threat to the continued successful use of antimicrobial agents for the treatment of bacterial infections.

Antimicrobial Resistance

Antimicrobial resistance poses a significant threat to the continued successful use of antimicrobial agents for the treatment of bacterial infections.

Allergy & Infectious Diseases

Allergies result from the hyperreactivity of the immune system to some environmental substance and can be life-threatening. Infectious diseases are caused by organisms including bacteria, viruses, fungi and parasites. They can be transmitted different ways, such as person-to-person. Here is the latest research on allergy and infectious diseases.