Biomaterial Database

A new conditional lethal mutator (dnaQ49) in Escherichia coli K12. 1978

T Horiuchi, and H Maki, and M Sekiguchi

A conditional lethal mutator, dnaQ49, was found in Escherichia coli K12. The dnaQ49 mutation caused stimulation of rifampicin-, nalidixic acid- and streptomycin-resistant mutation frequencies 100 to 2000 fold at 30 degrees C and the frequencies were further increased 50 to 100 fold at 35 degrees C or higher temperatures. Cells carrying dnaQ49 were unable to grow in salt-free L-broth at 44.5 degrees C, and DNA synthesis but not protein synthesis of the cells was suppressed under the restrictive conditions. The dnaQ gene was located at about 5 min on the E. coli linkage map and the order of the genes residing in this region was determined to be ton A-dnaE-metD-dnaQ-pro A.

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
D009268	Nalidixic Acid	A synthetic 1,8-naphthyridine antimicrobial agent with a limited bacteriocidal spectrum. It is an inhibitor of the A subunit of bacterial DNA GYRASE.	Nalidixin,Nalidixate Sodium,Nalidixate Sodium Anhydrous,Nevigramon,Sodium Nalidixic Acid, Anhydrous,Sodium Nalidixic Acid, Monohydrate,Acid, Nalidixic,Anhydrous, Nalidixate Sodium,Sodium Anhydrous, Nalidixate,Sodium, Nalidixate
D002874	Chromosome Mapping	Any method used for determining the location of and relative distances between genes on a chromosome.	Gene Mapping,Linkage Mapping,Genome Mapping,Chromosome Mappings,Gene Mappings,Genome Mappings,Linkage Mappings,Mapping, Chromosome,Mapping, Gene,Mapping, Genome,Mapping, Linkage,Mappings, Chromosome,Mappings, Gene,Mappings, Genome,Mappings, Linkage
D002876	Chromosomes, Bacterial	Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.	Bacterial Chromosome,Bacterial Chromosomes,Chromosome, Bacterial
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D004352	Drug Resistance, Microbial	The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).	Antibiotic Resistance,Antibiotic Resistance, Microbial,Antimicrobial Resistance, Drug,Antimicrobial Drug Resistance,Antimicrobial Drug Resistances,Antimicrobial Resistances, Drug,Drug Antimicrobial Resistance,Drug Antimicrobial Resistances,Drug Resistances, Microbial,Resistance, Antibiotic,Resistance, Drug Antimicrobial,Resistances, Drug Antimicrobial
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
D005804	Genes, Lethal	Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.	Alleles, Lethal,Allele, Lethal,Gene, Lethal,Lethal Allele,Lethal Alleles,Lethal Gene,Lethal Genes
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D012293	Rifampin	A semisynthetic antibiotic produced from Streptomyces mediterranei. It has a broad antibacterial spectrum, including activity against several forms of Mycobacterium. In susceptible organisms it inhibits DNA-dependent RNA polymerase activity by forming a stable complex with the enzyme. It thus suppresses the initiation of RNA synthesis. Rifampin is bactericidal, and acts on both intracellular and extracellular organisms. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p1160)	Rifampicin,Benemycin,Rifadin,Rimactan,Rimactane,Tubocin