Biomaterial Database

The dissimilar mutational consequences of SN1 and SN2 DNA alkylation pathways: clues from the mutational specificity of dimethylsulphate in the lacI gene of Escherichia coli. 1989

M Zielenska, and M J Horsfall, and B W Glickman

Biology Department, York University, Toronto, Ontario, Canada.

The mutational specificity of the monofunctional alkylating agent dimethylsulphate has been determined through the DNA sequence characterization of 121 lacI-d mutations of Escherichia coli. The predominant mutation induced was the G:C----A:T transition (75%). Transversions constituted 20% of all mutation with the greatest contribution being that of G:C----T:A events (12%). Runs of G:C base pairs were the preferred sites of frameshift mutation. One 6-bp sequence (5'-CCCGCG-3') appeared to be highly susceptible to all classes of mutation and events within this sequence accounted for 33% of all mutations characterized. Although the distribution of G:C----A:T mutations appeared non-random, the site-specificity observed was quite different from that reported for SN1 alkylating agents. The results of this study highlight the differences between the consequences of SN1 and SN2 alkylation pathways.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
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
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
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
D005798	Genes, Bacterial	The functional hereditary units of BACTERIA.	Bacterial Gene,Bacterial Genes,Gene, Bacterial
D000477	Alkylating Agents	Highly reactive chemicals that introduce alkyl radicals into biologically active molecules and thereby prevent their proper functioning. Many are used as antineoplastic agents, but most are very toxic, with carcinogenic, mutagenic, teratogenic, and immunosuppressant actions. They have also been used as components in poison gases.	Alkylating Agent,Alkylator,Alkylators,Agent, Alkylating,Agents, Alkylating
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D013463	Sulfuric Acid Esters	Organic esters of sulfuric acid.	Sulfates, Organic,Thiosulfuric Acid Esters,Organic Sulfates,Esters, Sulfuric Acid,Esters, Thiosulfuric Acid
D013464	Sulfuric Acids	Inorganic and organic derivatives of sulfuric acid (H2SO4). The salts and esters of sulfuric acid are known as SULFATES and SULFURIC ACID ESTERS respectively.	Acids, Sulfuric