The IrrE protein of Deinococcus radiodurans R1 is a novel regulator of recA expression.
IRS24 is a DNA damage-sensitive strain of Deinococcus radiodurans strain 302 carrying a mutation in an uncharacterized locus designated irrE. Five overlapping cosmids capable of restoring ionizing radiation resistance to IRS24 were isolated from a genomic library. The ends of each cloned insert were sequenced, and these sequences were used to localize irrE to a 970-bp region on chromosome I of D. radiodurans R1. The irrE gene corresponds to coding sequence DR0167 in the R1 genome. The irrE gene encodes a 35,000-Da protein that has no similarity to any previously characterized peptide. The irrE locus of R1 was also inactivated by transposon mutagenesis, and this strain was sensitive to ionizing radiation, UV light, and mitomycin C. Preliminary findings indicate that IrrE is a novel regulatory protein that stimulates transcription of the recA gene following exposure to ionizing radiation.
Earl
Ashlee M
AM
Department of Biological Sciences, Louisiana State University and A & M College, Baton Rouge 70803, USA.
Mohundro
Michael M
MM
Mian
I Saira
IS
Battista
John R
JR
D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage; D004260:DNA Repair; D004251:DNA Transposable Elements; D034301:Deinococcus / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects*; D015964:Gene Expression Regulation, Bacterial; D016685:Mitomycin / Q000494:pharmacology; D016254:Mutagenesis, Insertional; D011836:Radiation Tolerance; D011839:Radiation, Ionizing; D011938:Rec A Recombinases / Q000235:genetics / Q000378:metabolism*; D014169:Transformation, Bacterial; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D016685:Mitomycin; D011938:Rec A Recombinases