Biomaterial Database

Mutator specificity of Escherichia coli alkB117 allele. 2006

Jadwiga Nieminuszczy, and Celina Janion, and Elzbieta Grzesiuk

Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa, Poland.

The Escherichia coli AlkB protein encoded by alkB gene was recently found to repair cytotoxic DNA lesions 1-methyladenine (1-meA) and 3-methylcytosine (3-meC) by using a novel iron-catalysed oxidative demethylation mechanism that protects the cell from the toxic effects of methylating agents. Mutation in alkB results in increased sensitivity to MMS and elevated level of MMS-induced mutations. The aim of this study was to analyse the mutational specificity of alkB117 in a system developed by J.H. Miller involving two sets of E. coli lacZ mutants, CC101-106 allowing the identification of base pair substitutions, and CC107-CC111 indicating frameshift mutations. Of the six possible base substitutions, the presence of alkB117 allele led to an increased level of GC-->AT transitions and GC-->TA and AT-->TA transversions. After MMS treatment the level of GC-->AT transitions increased the most, 22-fold. Among frameshift mutations, the most numerous were -2CG, -1G, and -1A deletions and +1G insertion. MMS treatment appreciably increased all of the above types of frameshifts, with additional appearance of the +1A insertion.

UI	MeSH Term	Description	Entries
D007763	Lac Operon	The genetic unit consisting of three structural genes, an operator and a regulatory gene. The regulatory gene controls the synthesis of the three structural genes: BETA-GALACTOSIDASE and beta-galactoside permease (involved with the metabolism of lactose), and beta-thiogalactoside acetyltransferase.	Lac Gene,LacZ Genes,Lactose Operon,Gene, Lac,Gene, LacZ,Genes, Lac,Genes, LacZ,Lac Genes,Lac Operons,LacZ Gene,Lactose Operons,Operon, Lac,Operon, Lactose,Operons, Lac,Operons, Lactose
D008741	Methyl Methanesulfonate	An alkylating agent in cancer therapy that may also act as a mutagen by interfering with and causing damage to DNA.	Methylmethane Sulfonate,Dimethylsulfonate,Mesilate, Methyl,Methyl Mesylate,Methyl Methylenesulfonate,Methylmesilate,Mesylate, Methyl,Methanesulfonate, Methyl,Methyl Mesilate
D009153	Mutagens	Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.	Clastogen,Clastogens,Genotoxin,Genotoxins,Mutagen
D003062	Codon	A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).	Codon, Sense,Sense Codon,Codons,Codons, Sense,Sense Codons
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
D006899	Mixed Function Oxygenases	Widely distributed enzymes that carry out oxidation-reduction reactions in which one atom of the oxygen molecule is incorporated into the organic substrate; the other oxygen atom is reduced and combined with hydrogen ions to form water. They are also known as monooxygenases or hydroxylases. These reactions require two substrates as reductants for each of the two oxygen atoms. There are different classes of monooxygenases depending on the type of hydrogen-providing cosubstrate (COENZYMES) required in the mixed-function oxidation.	Hydroxylase,Hydroxylases,Mixed Function Oxidase,Mixed Function Oxygenase,Monooxygenase,Monooxygenases,Mixed Function Oxidases,Function Oxidase, Mixed,Function Oxygenase, Mixed,Oxidase, Mixed Function,Oxidases, Mixed Function,Oxygenase, Mixed Function,Oxygenases, Mixed Function
D000483	Alleles	Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.	Allelomorphs,Allele,Allelomorph
D016296	Mutagenesis	Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.	Mutageneses
D016368	Frameshift Mutation	A type of mutation in which a number of NUCLEOTIDES deleted from or inserted into a protein coding sequence is not divisible by three, thereby causing an alteration in the READING FRAMES of the entire coding sequence downstream of the mutation. These mutations may be induced by certain types of MUTAGENS or may occur spontaneously.	Mutation, Frameshift,Frame Shift Mutation,Out-of-Frame Deletion,Out-of-Frame Insertion,Out-of-Frame Mutation,Deletion, Out-of-Frame,Deletions, Out-of-Frame,Frame Shift Mutations,Frameshift Mutations,Insertion, Out-of-Frame,Insertions, Out-of-Frame,Mutation, Frame Shift,Mutation, Out-of-Frame,Mutations, Frame Shift,Mutations, Frameshift,Mutations, Out-of-Frame,Out of Frame Deletion,Out of Frame Insertion,Out of Frame Mutation,Out-of-Frame Deletions,Out-of-Frame Insertions,Out-of-Frame Mutations
D017354	Point Mutation	A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.	Mutation, Point,Mutations, Point,Point Mutations