EC Number   |
General Information |
Reference |
|---|
   4.2.99.B1 | evolution |
AtPolIs are functionally equipped to play a role in short-patch BER suggesting a major role of AtPolIB in a predicted long-patch BER sub-pathway. The acquisition of insertion 1 in the polymerization domain of AtPolIs is a key component in their evolution as BER associated and replicative DNAPs |
747641 |
| 4.2.99.B1 | evolution |
enzyme Rev1 is a member of the Y-family of DNA polymerases. Characterization of Rev1 domains in relation to BER activities |
748781 |
| 4.2.99.B1 | malfunction |
Detection of stable DNA-protein crosslinks (DPC) between Pol beta and dL in intact cells. Formation of BER-mediated DNA-protein crosslinks, formation of oxidative polbeta-DPC in vivo. Pol beta-DPC are subsequently targeted for ubiquitylation and rapid proteolysis, which is expected to generate 5'-peptidyl-dL-DNA adducts. Inhibition of theproteasome prevents removal of Pol beta-DPC (3B), leading to their toxic accumulation with cell killing and perhaps other consequences. Mitochondrial DNA polymerase gamma (Pol gamma), which harbors a 5'-dRp lyase similar to that of Pol beta, is also trapped by 5'-dL |
747638 |
| 4.2.99.B1 | malfunction |
mouse embryonic fibroblasts (MEFs) deficient in enzyme PolB show significantly increased sensitivity to methyl methanesulfonate (MMS). PolB deficiency results in an increased apoptotic cell fraction and chromosomal aberrations after MMS treatment. MMS hypersensitivity can be reversed by the dRP lyase domain of PolB, this hypersensitivity is mainly caused by Sn-BER deficiency. A contribution of PolB-independent repair mechanisms is also likely because of the increased sensitivity of PolB-knockout MEFs at relatively high MMS concentrations |
748493 |
| 4.2.99.B1 | malfunction |
three Pol beta enzymes modified at position 72 with aminooxy or hydrazinyl analogues of lysine form transient covalent bonds with the 5'-dRP moiety of the damaged DNA, in the form of an oxime or hydrazone, respectively. Both types of enzyme DNA intermediates are ultimately resolved by the lyase activities of each of the modified enzymes. The formation and resolution of these E-S complexes proceed with diminished kinetics, and with an altered pH profile compared to wild-type. Comparison of base excision repair (BER) reaction with wild-type and modified Pol beta enzymes: while the wild-type enzyme performs BER very efficiently, the BER activity of the three modified enzymes is greatly reduced. The overall BER efficiency of our modified Pol beta enzymes reflects predominantly their ability to remove the 5'-dRP group, the modified proteins demonstrate poor lyase activity |
747135 |
| 4.2.99.B1 | metabolism |
because DNA polymerase lambda (PolL) belongs to the same family X and has similarities in activity and structure to PolB, PolL may play a backup role in the absence of PolB |
748493 |
| 4.2.99.B1 | more |
residue AtPollB-Lys593 acts as nucleophile for lyase activity and is responsible for 5'-RP lyase activity in AtPolIB. 5'-RP lyase activity is mapped to a single amino acid in insertion 1 |
747641 |
| 4.2.99.B1 | more |
study of the lyase activity of human DNA polymerase beta using analogues of the intermediate Schiff base complex |
747135 |
| 4.2.99.B1 | physiological function |
accurate and efficient repair by nonhomologous end joining NHEJ of double-strand breaks with such damage similarly requires 5'-deoxyribose phosphate/abasic lyase activity provided by Ku70. Ku70 nicks DNA 3' of an abasic site by a mechanism involving a Schiff base covalent intermediate with the abasic site. Ku70 is essential for efficient removal of abasic sites near double strand breaks and, consistent with this result, joining of such breaks is specifically reduced in cells complemented with a lyase-attenuated Ku mutant |
705892 |
| 4.2.99.B1 | physiological function |
DNA polymerase beta (Pol beta) is a key enzyme in mammalian base excision repair (BER), contributing stepwise 5'-deoxyribose phosphate (dRP) lyase and gap-filling DNA polymerase activities. The lyase reaction is believed to occur via a beta-elimination reaction following the formation of a Schiff base between the dRP group at the pre-incised apurinic/apyrimidinic site and the epsilon-amino group of Lys72 |
747129 |
