Exonuclease of human DNA polymerase gamma disengages its strand displacement function.
Mitochondrion
; 13(6): 592-601, 2013 Nov.
Article
em En
| MEDLINE
| ID: mdl-23993955
ABSTRACT
Pol γ, the only DNA polymerase found in human mitochondria, functions in both mtDNA repair and replication. During mtDNA base-excision repair, gaps are created after damaged base excision. Here we show that Pol γ efficiently gap-fills except when the gap is only a single nucleotide. Although wild-type Pol γ has very limited ability for strand displacement DNA synthesis, exo(-) (3'-5' exonuclease-deficient) Pol γ has significantly high activity and rapidly unwinds downstream DNA, synthesizing DNA at a rate comparable to that of the wild-type enzyme on a primer-template. The catalytic subunit Pol γA alone, even when exo(-), is unable to synthesize by strand displacement, making this the only known reaction of Pol γ holoenzyme that has an absolute requirement for the accessory subunit Pol γB.
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MEDLINE
Assunto principal:
DNA Mitocondrial
/
DNA Polimerase Dirigida por DNA
/
Exonucleases
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article