English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/38995
Compartir / Impacto:
Título : A Conserved Insertion in Protein-primed DNA Polymerases is Involved in Primer Terminus Stabilisation
Autor : Dufour, Emmanuelle; Rodríguez, Irene; Lázaro, José M.; Vega, Miguel de; Salas, Margarita
Palabras clave : Linear DNA replication
Protein priming
Bacteriophage φ29
Fecha de publicación : 22-ago-2003
Editor: Elsevier
Citación : Journal of Molecular Biology 331(4): 781-794 (2003)
Resumen: Protein-primed DNA polymerases form a subgroup of the eukaryotic-type DNA polymerases family, also called family B or α-like. A multiple amino acid sequence alignment of this subgroup of DNA polymerases led to the identification of two insertions, TPR-1 and TPR-2, in the polymerisation domain. We showed previously that Asp332 of the TPR-1 insertion of ø29 DNA polymerase is involved in the correct orientation of the terminal protein (TP) for the initiation of replication. In this work, the functional role of two other conserved residues from TPR-1, Lys305 and Tyr315, has been analysed. The four mutant derivatives constructed, K305I, K305R, Y315A and Y315F, displayed a wild-type 3′–5′ exonuclease activity on single-stranded DNA. However, when assayed on double-stranded DNA such activity was higher than that of the wild-type enzyme. This activity led to a reduced pol/exo ratio, suggesting a defect in stabilising the primer terminus at the polymerase active site. On the other hand, although mutant polymerases K305I and Y315A were able to couple processive DNA polymerisation to strand displacement, they were severely impaired in ø29 TP-DNA replication. The possible role of the TPR-1 insertion in the set of interactions with the nascent chain during the first steps of TP-DNA replication is discussed.
Versión del editor: http://dx.doi.org/10.1016/S0022-2836(03)00788-5
URI : http://hdl.handle.net/10261/38995
ISSN: 0022-2836
DOI: http://dx.doi.org/10.1016/S0022-2836(03)00788-5
Aparece en las colecciones: (CBM) Artículos
Ficheros en este ítem:
No hay ficheros asociados a este ítem.
Mostrar el registro completo

NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.