Data/hora: 10/06/2024 12:08:16

Provedor de dados: | 5
País: | France
Título: | Les ADN polymérases B et D de l'Archaea hyperthermophile, Pyrococcus abyssi : contribution à l'étude des relations structure-fonction
Autores: | Castrec, Benoit.
Data: | 2009-11-06
Ano: | 2009
Palavras-chave: | Thermostability; Interactions; Motifs; DNA replication; RF C; PCNA; DNA polymerases; Archaea; Thermostabilité; Interactions; Motifs; Réplication de l'ADN; RF C; PCNA; ADN polymérases; Archaea.
Resumo: | DNA replication is a functionally conserved mechanism among the three domains of life. This processus is performed by DNA polymerases with two accessories factors, PCNA and RF-C, sliding clamp and clamp loader, respectively. Our model of study, the Euryarchaeota Pyrococcus abyssi, possesses one monomeric DNA polymerase, belonging to the Family B, and one heterodimeric DNA polymerase, belonging to the Family D. Usually, proteins interact with PCNA at a hydrophobic pocket which is formed by the IDCL (interdomain connecting loop) and the C-terminus. These interactions are mediated through common motifs like the PIP box (motif PCNA interacting Protein). We have demonstrated that Pol B has just one PIP box motif at the C-terminus, while Pol D has two PIP-type motifs, at the N- and C terminus, respectively, that interact with PCNA. Besides, directed mutagenesis has been performed at different sites into the hydrophobic pocket of PCNA and permit to give prominence to that Pol D precisely interacts at the C terminus of PCNA. In the same way, we have demonstrated that RF-C, via its PIP box motif, can maintain PCNA on DNA and can block the Pol D/PCNA complex. In addition, a glycine-rich motif has been characterised in Pol D. This motif, renamed PYF box, is implicated in thermostability of this enzyme and could participate to the interactions between subunits DP1 and DP2. Finally, preliminary work on fluorescence spectroscopy gives us some perspectives in the study of nucleo-proteic complexes. The investigation of motifs, implied in structure-function relationship, let us to complete our knowledge about mechanisms of replicative systems in Archaea and more precisely on Pol D, which is still largely unknown.
Tipo: | Text
Idioma: | Francês
Identificador: | http://archimer.ifremer.fr/doc/2009/these-6940.pdf
Editor: | Université européenne de Bretagne
Relação: | http://archimer.ifremer.fr/doc/00000/6940/
Formato: | application/pdf