The Family X DNA Polymerase from Deinococcus radiodurans Adopts a Non-standard Extended Conformation
AUTOR(ES)
Leulliot, Nicolas
FONTE
American Society for Biochemistry and Molecular Biology
RESUMO
Deinococcus radiodurans is an extraordinarily radioresistant bacterium that is able to repair hundreds of radiation-induced double-stranded DNA breaks. One of the players in this pathway is an X family DNA polymerase (PolXDr). Deletion of PolXDr has been shown to decrease the rate of repair of double-stranded DNA breaks and increase cell sensitivity to gamma-rays. A 3′→5′ exonuclease activity that stops cutting close to DNA loops has also been demonstrated. The present crystal structure of PolXDr solved at 2.46-Å resolution reveals that PolXDr has a novel extended conformation in stark contrast to the closed “right hand” conformation commonly observed for DNA polymerases. This extended conformation is stabilized by the C-terminal PHP domain, whose putative nuclease active site is obstructed by its interaction with the polymerase domain. The overall conformation and the presence of non standard residues in the active site of the polymerase X domain makes PolXDr the founding member of a novel class of polymerases involved in DNA repair but whose detailed mode of action still remains enigmatic.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2673268Documentos Relacionados
- A non-standard optimal control problem arising in an economics application
- A quarter of the medical jobs advertised in the NHS are for non-standard posts
- PCR amplification of DNA containing non-standard base pairs by variants of reverse transcriptase from Human Immunodeficiency Virus-1
- V(D)J recombination intermediates and non-standard products in XRCC4-deficient cells.
- Differential discrimination of DNA polymerase for variants of the non-standard nucleobase pair between xanthosine and 2,4-diaminopyrimidine, two components of an expanded genetic alphabet.
