Enzymes
UniProtKB help_outline | 4 proteins |
Enzyme class help_outline |
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Reaction participants Show >> << Hide
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Namehelp_outline
(2'-deoxyribonucleoside 5'-methylphosphotriester)-DNA
Identifier
RHEA-COMP:14463
Reactive part
help_outline
- Name help_outline a methylphosphotriester deoxyribonucleoside residue Identifier CHEBI:140286 Charge 0 Formula C6H10O5PR SMILEShelp_outline *[C@@H]1O[C@H](COP(=O)(*)OC)[C@@H](O*)C1 2D coordinates Mol file for the small molecule Search links Involved in 1 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
L-cysteinyl-[protein]
Identifier
RHEA-COMP:10131
Reactive part
help_outline
- Name help_outline L-cysteine residue Identifier CHEBI:29950 Charge 0 Formula C3H5NOS SMILEShelp_outline C(=O)(*)[C@@H](N*)CS 2D coordinates Mol file for the small molecule Search links Involved in 123 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
2'-deoxyribonucleotide-DNA
Identifier
RHEA-COMP:14462
Reactive part
help_outline
- Name help_outline a deoxyribonucleotide residue Identifier CHEBI:140284 Charge -1 Formula C5H7O5PR SMILEShelp_outline *[C@@H]1O[C@H](COP(=O)(*)[O-])[C@@H](O*)C1 2D coordinates Mol file for the small molecule Search links Involved in 29 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,176 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
S-methyl-L-cysteinyl-[protein]
Identifier
RHEA-COMP:10132
Reactive part
help_outline
- Name help_outline S-methyl-L-cysteine residue Identifier CHEBI:82612 Charge 0 Formula C4H7NOS SMILEShelp_outline CSC[C@H](N-*)C(-*)=O 2D coordinates Mol file for the small molecule Search links Involved in 5 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:56324 | RHEA:56325 | RHEA:56326 | RHEA:56327 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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EcoCyc help_outline |
Publications
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Phosphotriester adducts (PTEs): DNA's overlooked lesion.
Jones G.D., Le Pla R.C., Farmer P.B.
In addition to reacting with DNA base moieties, many chemical genotoxins also react with the oxygen atoms of the internucleotidic phosphodiester linkages to form phosphotriester adducts (PTEs). In view of their stability under physiological conditions, it has been suggested that PTEs may be useful ... >> More
In addition to reacting with DNA base moieties, many chemical genotoxins also react with the oxygen atoms of the internucleotidic phosphodiester linkages to form phosphotriester adducts (PTEs). In view of their stability under physiological conditions, it has been suggested that PTEs may be useful biomarkers for measuring cumulative genotoxin exposure. The methodology for their determination is varied and still not completely developed but includes determination of hydrolysis products and (32)P-postlabelling approaches. More recently, transalkylation and direct mass spectrometry techniques have been devised, which give extra chemical information on the structures of the PTEs. The proportion of DNA damage formed as PTEs is much greater with SN1 compared to SN2 alkylating agents, and it has been shown in DNA that the formation of PTEs is partially sequence dependent. PTEs have been considered to be refractory to repair in mammalian cells but repair mechanisms have been found in prokaryotic cells, e.g. PTEs in Escherichia coli are repaired by O(6)-methylguanine-DNA methyltransferase (O(6)-MGT or Ada protein). However, studies on in vivo persistence of PTEs in mammalian systems have not ruled out the possibility of a contribution from an active repair process for PTEs. The biological significance of PTEs is largely unstudied and unknown, although effects of PTEs on DNA polymerases, and some exo- and endonucleases have been observed. Also site-specific PTEs impair the repair processing of adjacent sites of DNA damage, which may be a biological mechanism of importance for these lesions. In this review, we will consider the analytical methods available for the determination of PTEs, their stability in vitro and in vivo, the mechanisms for their repair, their possible biological significance and their potential role as biomarkers in human molecular epidemiology studies. << Less
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Methyl phosphotriesters in alkylated DNA are repaired by the Ada regulatory protein of E. coli.
McCarthy T.V., Lindahl T.
The E. coli ada+ gene product that controls the adaptive response to alkylating agents has been purified to apparent homogeneity using an overproducing expression vector system. This 39 kDa protein repairs 0(6)-methylguanine and 0(4)-methylthymine residues in alkylated DNA by transfer of the methy ... >> More
The E. coli ada+ gene product that controls the adaptive response to alkylating agents has been purified to apparent homogeneity using an overproducing expression vector system. This 39 kDa protein repairs 0(6)-methylguanine and 0(4)-methylthymine residues in alkylated DNA by transfer of the methyl group from the base to a cysteine residue in the protein itself. The Ada protein also corrects one of the stereoisomers of methyl phosphotriesters in DNA by the same mechanism, while the other isomer is left unrepaired. Different cysteine residues in the Ada protein are used as acceptors in the repair of methyl groups derived from phosphotriesters and base residues. << Less
Nucleic Acids Res. 13:2683-2698(1985) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.
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Multiple species of Bacillus subtilis DNA alkyltransferase involved in the adaptive response to simple alkylating agents.
Morohoshi F., Munakata N.
Three molecular species of methyl-accepting proteins exist in Bacillus subtilis cells, which collect methyl groups from methylated DNA. A 20-kilodalton (kDa) protein was constitutively present in the cells of the ada+ (proficient in adaptive response) strain as well as in those of six ada (deficie ... >> More
Three molecular species of methyl-accepting proteins exist in Bacillus subtilis cells, which collect methyl groups from methylated DNA. A 20-kilodalton (kDa) protein was constitutively present in the cells of the ada+ (proficient in adaptive response) strain as well as in those of six ada (deficient in adaptive response) mutant strains and was assigned to the O6-methylguanine:DNA methyltransferase. Another species of O6-methylguanine:DNA methyltransferase, which had a molecular size of 22 kDa, emerged after adaptive treatment of the ada+ but not any of the ada mutant cells. A 27-kDa methyl-accepting protein, which preferred methylated poly(dT) to methylated calf thymus DNA as a substrate, was assigned to the methylphosphotriester:DNA methyltransferase. It was produced, after adaptive treatment, in the cells of ada+, ada-3, ada-4, and ada-6 strains but not in the cells of ada-1, ada-2, or ada-5 strains. These results support and extend our proposition that ada mutants can be classified into two groups; one (the ada-4 group) is defective only in the inducible synthesis of O6-methylguanine:DNA methyltransferase (22-kDa protein), and the other (the ada-1 group) is deficient in the adaptive response in toto. The finding that inducible and constitutive methyltransferases reside in different molecular species of methyl-accepting proteins is intriguing compared with the regulatory mechanisms of the adaptive response to simple alkylating agents in other organisms. << Less