Polymerase θ-helicase efficiently unwinds DNA and RNA-DNA hybrids.
J Biol Chem
; 293(14): 5259-5269, 2018 04 06.
Article
en En
| MEDLINE
| ID: mdl-29444826
ABSTRACT
POLQ is a unique multifunctional replication and repair gene that encodes for a N-terminal superfamily 2 helicase and a C-terminal A-family polymerase. Although the function of the polymerase domain has been investigated, little is understood regarding the helicase domain. Multiple studies have reported that polymerase θ-helicase (Polθ-helicase) is unable to unwind DNA. However, it exhibits ATPase activity that is stimulated by single-stranded DNA, which presents a biochemical conundrum. In contrast to previous reports, we demonstrate that Polθ-helicase (residues 1-894) efficiently unwinds DNA with 3'-5' polarity, including DNA with 3' or 5' overhangs, blunt-ended DNA, and replication forks. Polθ-helicase also efficiently unwinds RNA-DNA hybrids and exhibits a preference for unwinding the lagging strand at replication forks, similar to related HELQ helicase. Finally, we find that Polθ-helicase can facilitate strand displacement synthesis by Polθ-polymerase, suggesting a plausible function for the helicase domain. Taken together, these findings indicate nucleic acid unwinding as a relevant activity for Polθ in replication repair.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
ADN Helicasas
/
ADN Polimerasa Dirigida por ADN
Límite:
Humans
Idioma:
En
Revista:
J Biol Chem
Año:
2018
Tipo del documento:
Article