Biomaterial Database

[Operator-constitutive mutation in the recA gene enhances radiation resistance of Escherichia coli]. 2009

V N Verbenko, and L V Kuznetsova, and E P Krup'ian, and A V Suslov

Plasmid pUC19-recAoc carrying a mutant allele of the recA gene, which plays the key role in the control of the SOS repair system and homologous recombinational repair, causes a 1.5-fold increase in radiation resistance of Escherichia coli DeltarecA cells, as compared to the wild-type recA+ cells. The protective effect of this plasmid is drastically reduced in mutant lexA3 recADelta21 deficient in the LexA protein and in induction of the SOS regulon. Plasmid pUC19-recAoc effectively suppresses UV sensitivity of the DeltarecA mutant. Mutation recAo20 allows constitutive high-level synthesis of the RecA protein. This mutation impairs the SOS box in the operator site of the recA gene and enhances heterology of the dimer LexA binding site. These data confirm that high level of the RecA protein synthesis per se is not sufficient for the expression of gamma-inducible functions and that the derepression of lexA-dependent genes, other than recA gene, is necessary for the complete induction of the SOS repair system.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D009875	Operator Regions, Genetic	The regulatory elements of an OPERON to which activators or repressors bind thereby effecting the transcription of GENES in the operon.	Operator Region,Operator Regions,Operator, Genetic,Genetic Operator,Genetic Operator Region,Genetic Operator Regions,Genetic Operators,Operator Region, Genetic,Operators, Genetic,Region, Genetic Operator,Region, Operator,Regions, Genetic Operator,Regions, Operator
D011836	Radiation Tolerance	The ability of some cells or tissues to survive lethal doses of IONIZING RADIATION. Tolerance depends on the species, cell type, and physical and chemical variables, including RADIATION-PROTECTIVE AGENTS and RADIATION-SENSITIZING AGENTS.	Radiation Sensitivity,Radiosensitivity,Sensitivity, Radiation,Tolerance, Radiation,Radiation Sensitivities,Radiation Tolerances,Radiosensitivities,Sensitivities, Radiation,Tolerances, Radiation
D011938	Rec A Recombinases	A family of recombinases initially identified in BACTERIA. They catalyze the ATP-driven exchange of DNA strands in GENETIC RECOMBINATION. The product of the reaction consists of a duplex and a displaced single-stranded loop, which has the shape of the letter D and is therefore called a D-loop structure.	Rec A Protein,RecA Protein,Recombinases, Rec A
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005720	Gamma Rays	Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.	Gamma Wave,Gamma Radiation,Nuclear X-Rays,Radiation, Gamma,X-Rays, Nuclear,Gamma Radiations,Gamma Ray,Gamma Waves,Nuclear X Rays,Nuclear X-Ray,Ray, Gamma,Wave, Gamma,Waves, Gamma,X Rays, Nuclear,X-Ray, Nuclear
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D012697	Serine Endopeptidases	Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.	Serine Endopeptidase,Endopeptidase, Serine,Endopeptidases, Serine
D013014	SOS Response, Genetics	An error-prone mechanism or set of functions for repairing damaged microbial DNA. SOS functions (a concept reputedly derived from the SOS of the international distress signal) are involved in DNA repair and mutagenesis, in cell division inhibition, in recovery of normal physiological conditions after DNA repair, and possibly in cell death when DNA damage is extensive.	SOS Response (Genetics),SOS Box,SOS Function,SOS Induction,SOS Region,SOS Repair,SOS Response,SOS System,Box, SOS,Function, SOS,Functions, SOS,Genetics SOS Response,Genetics SOS Responses,Induction, SOS,Inductions, SOS,Region, SOS,Regions, SOS,Repair, SOS,Repairs, SOS,Response, Genetics SOS,Response, SOS,Response, SOS (Genetics),Responses, Genetics SOS,Responses, SOS,Responses, SOS (Genetics),SOS Functions,SOS Inductions,SOS Regions,SOS Repairs,SOS Responses,SOS Responses (Genetics),SOS Responses, Genetics,SOS Systems,System, SOS,Systems, SOS