Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 4.2.99.18 extracted from

  • Mantha, A.K.; Oezguen, N.; Bhakat, K.K.; Izumi, T.; Braun, W.; Mitra, S.
    Unusual role of a cysteine residue in substrate binding and activity of human AP-endonuclease 1 (2008), J. Mol. Biol., 379, 28-37.
    View publication on PubMedView publication on EuropePMC
Search for more literature for 4.2.99.18

Cloned(Commentary)

Cloned (Comment) Organism
wild-type APE1 and its Cys mutants are expressed as His-tag fusion polypeptides in Escherichia coli Homo sapiens

Protein Variants

Protein Variants Comment Organism
C138S repair activity is not affected Homo sapiens
C138S/C99S double mutants Homo sapiens
C208S repair activity is not affected Homo sapiens
C296S repair activity is not affected Homo sapiens
C310S repair activity is not affected Homo sapiens
C65S repair activity is not affected Homo sapiens
C65S/C99S double mutants Homo sapiens
C93S repair activity is not affected Homo sapiens
C99S the mutant loses affinity for DNA and its activity is inhibited by 10 mM Mg2+, involvement of Cys99 in APE1's substrate binding and catalysis provides an example of involvement of a residue far from the active site Homo sapiens

Inhibitors

Inhibitors Comment Organism Structure
Mg2+ AP-endonuclease activity of the C99S mutant as well as of the double mutants C138S/C99S and C65S/C99S is strongly inhibits in the presence of 10 mM Mg2+. Increasing Mg2+ concentration to 10 mM inhibited product formation by 5.4-fold. At 20 mM Mg2+, the product formation with wild-type APE1 is inhibited 4.2-fold and with the C99S mutant 14-fold relative to the activity of the wild-type protein in 5 mM Mg2+ Homo sapiens

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
0.0000368
-
 43-mer oligonucleotide containing the AP-site analog THF at nt 31 wild-type, presence of 2 mM Mg2+ Homo sapiens
0.0000536
-
 43-mer oligonucleotide containing the AP-site analog THF at nt 31 mutant C99S, presence of 2 mM Mg2+ Homo sapiens

Metals/Ions

Metals/Ions Comment Organism Structure
Mg2+ Mg2+, with potential binding sites A and B, binds at the B site of wild-type APE1-substrate complex and moves to the A site after cleavage occurs Homo sapiens

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
additional information Homo sapiens APEs have 2 intrinsic activities in DNA repair. They act as an endonuclease in cleaving AP sites to generate 3' OH and 5' phosphodeoxyribose termini. They also act as a 3' phosphodiesterase/exonuclease to remove 3' blocking phosphodeoxyribose or its fragments generated during strand breaks, and by reactive oxygen species or DNA glycosylases that excise oxidized bases in the first step of base excision repair ?
-
 ?
additional information Homo sapiens the key function is to produce a 3' OH terminus that serves as a primer for repair synthesis. ?
-
 ?

Organism

Organism UniProt Comment Textmining
Homo sapiens
-
-
-

Purification (Commentary)

Purification (Comment) Organism
after affinity purification and cleavage of the His-tag, the untagged proteins to near homogeneity are purified by fast protein liquid chromatography using heparin-sepharose Homo sapiens

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
additional information
-
 10 mM Mg2+, all Cys mutants except those with C99S mutation are at least as active as the wild-type APE1 Homo sapiens
additional information
-
 activity of Cys99 mutants is comparable to that of the wild-type in 0.5 or 2mM Mg2+, while only the Cys99 mutants are strongly inhibited at 5 mM and higher Mg2+ concentration Homo sapiens
additional information
-
 Cys99 in hAPE1 as a critical residue modulating function for ensuring optimum activity Homo sapiens

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
43-mer oligonucleotide containing the AP-site analog tetrahydrofuran at nt 31
-
 Homo sapiens ?
-
 ?
43-mer oligonucleotide containing the AP-site analog THF at nt 31
-
 Homo sapiens ?
-
 ?
additional information APEs have 2 intrinsic activities in DNA repair. They act as an endonuclease in cleaving AP sites to generate 3' OH and 5' phosphodeoxyribose termini. They also act as a 3' phosphodiesterase/exonuclease to remove 3' blocking phosphodeoxyribose or its fragments generated during strand breaks, and by reactive oxygen species or DNA glycosylases that excise oxidized bases in the first step of base excision repair Homo sapiens ?
-
 ?
additional information the key function is to produce a 3' OH terminus that serves as a primer for repair synthesis. Homo sapiens ?
-
 ?

Synonyms

Synonyms Comment Organism
AP-endonuclease 1
-
 Homo sapiens
APE1
-
 Homo sapiens
APE1/Ref-1
-
 Homo sapiens
hAPE1
-
 Homo sapiens

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
37
-
 assay at Homo sapiens

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
2.91
-
 43-mer oligonucleotide containing the AP-site analog THF at nt 31 mutant C99S, presence of 2 mM Mg2+ Homo sapiens
3.36
-
 43-mer oligonucleotide containing the AP-site analog THF at nt 31 wild-type, presence of 2 mM Mg2+ Homo sapiens

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
8.5
-
 assay at Homo sapiens