Biomaterial Database

Saccharomyces cerevisiae 3-methyladenine DNA glycosylase has homology to the AlkA glycosylase of E. coli and is induced in response to DNA alkylation damage. 1990

J Chen, and B Derfler, and L Samson

Laboratory of Toxicology, Harvard School of Public Health, Boston, MA 02115.

We previously cloned a DNA fragment from Saccharomyces cerevisiae that suppressed the alkylation sensitivity of Escherichia coli glycosylase deficient mutants and we showed that it apparently contained a gene for 3-methyl-adenine DNA glycosylase (MAG). Here we establish the identity of the MAG gene by sequence analysis and describe its in vivo function and expression in yeast cells. The MAG DNA glycosylase specifically protects yeast cells against the killing effects of alkylating agents. It does not protect cells against mutation; indeed, it appears to generate mutations which presumably result from those apurinic sites produced by the glycosylase that escape further repair. The MAG gene, which we mapped to chromosome V, is not allelic with any of the RAD genes and appears to be allelic to the unmapped MMS-5 gene. From its sequence the MAG glycosylase is predicted to contain 296 amino acids and have a molecular weight of 34,293 daltons. A 137 amino acid stretch of the MAG glycosylase displays 27.0% identity and 63.5% similarity with the E. coli AlkA glycosylase. Transcription of the MAG gene, like that of the E. coli alkA gene, is greatly increased when yeast cells are exposed to relatively non-toxic levels of alkylating agents.

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
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
D009699	N-Glycosyl Hydrolases	A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.	Glycoside Hydrolases, Nitrogen-linked,Hydrolases, N-Glycosyl,Nucleosidase,Nucleosidases,Nucleoside Hydrolase,Nitrogen-linked Glycoside Hydrolases,Nucleoside Hydrolases,Glycoside Hydrolases, Nitrogen linked,Hydrolase, Nucleoside,Hydrolases, N Glycosyl,Hydrolases, Nitrogen-linked Glycoside,Hydrolases, Nucleoside,N Glycosyl Hydrolases,Nitrogen linked Glycoside Hydrolases
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
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
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D004260	DNA Repair	The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones.	DNA Damage Response
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
D000478	Alkylation	The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.	Alkylations
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein