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Literature summary for 3.6.1.71 extracted from

  • Hanaoka, K.; Tanaka, W.; Kayanuma, M.; Shoji, M.
    A QM/MM study of the 5'-AMP DNA hydrolysis of aprataxin (2015), Chem. Phys. Lett., 631-632, 16-20 .
No PubMed abstract available
Search for more literature for 3.6.1.71

Protein Variants

Protein Variants Comment Organism
H138A site-directed mutagenesis, mutation of His138 to alanine does not completely abolish the catalytic activity, the residual activity is 25% of the wild-type enzyme activity. The DNA deadenylation reaction catalyzed by the H138A mutant can proceed by the protonated substrate Homo sapiens

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
additional information Homo sapiens aprataxin hydrolyses abnormal 5'-AMP DNA termini formed in abortive DNA ligations ?
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 ?

Organism

Organism UniProt Comment Textmining
Homo sapiens Q7Z2E3
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Reaction

Reaction Comment Organism Reaction ID
adenosine-5'-diphospho-5'-(ribonucleotide)-[DNA] + H2O = AMP + 5'-phospho-(ribonucleotide)-[DNA] the catalytic reaction proceeds in three steps: substrate protonation, DNA deadenylation and histidine-AMP intermediate hydrolysis. The calculated activation energies for the second and third reactions are 19.0 and 10.5 kcal/mol, which can be attributed to a penta-coordinated AMP-phosphoryl formation and closing of a water molecule, respectively. A histidine-AMP intermediate is hydrolyzed easily in the third step when a water molecule closes within 3 A to the phosphorus nucleus Homo sapiens
a
adenosine-5'-diphospho-5'-[DNA] + H2O = AMP + phospho-5'-[DNA] the catalytic reaction proceeds in three steps: substrate protonation, DNA deadenylation and histidine-AMP intermediate hydrolysis. The calculated activation energies for the second and third reactions are 19.0 and 10.5 kcal/mol, which can be attributed to a penta-coordinated AMP-phosphoryl formation and closing of a water molecule, respectively. A histidine-AMP intermediate is hydrolyzed easily in the third step when a water molecule closes within 3 A to the phosphorus nucleus Homo sapiens
a

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
additional information aprataxin hydrolyses abnormal 5'-AMP DNA termini formed in abortive DNA ligations Homo sapiens ?
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 ?

Synonyms

Synonyms Comment Organism
aprataxin
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 Homo sapiens
APTX
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 Homo sapiens

General Information

General Information Comment Organism
evolution aprataxin (APTX) belongs to a family of histidine triad (HIT) enzymes. Mutation of His138 to alanine does not completely abolish the catalytic activity; the residual activity is 25% of the wild-type enzyme activity. The DNA deadenylation reaction catalyzed by the H138A mutant can proceed by the protonated substrate Homo sapiens
malfunction mutations of the APTX gene cause neurological diseases such as ataxia oculomotor aparaxia type 1 (AOA1) Homo sapiens
additional information active site structure of APTX, and molecular reaction mechanism, modeling, overview. General acid-base catalysis of APTX with and important role of His138 as a general acid. The second step, the histidine-AMP intermediate hydrolysis, can proceed with the aid of the product DNA phosphate without a general base residue Homo sapiens
physiological function 5'-AMP DNA hydrolysis of aprataxin, energy profile of the APTX catalytic reaction and the protonate states, by quantum mechanical/molecular mechanical (QM/MM) calculations and modeling, overview. Aprataxin hydrolyses abnormal 5'-AMP DNA termini formed in abortive DNA ligations, it is an important DNA repair enzyme Homo sapiens