English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/167283
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE
Exportar a otros formatos:


Noncatalytic aspartate at the exonuclease domain of proofreading DNA polymerases regulates both degradative and synthetic activities

AuthorsPrado, A. del; Franco-Echevarría, E.; González, Beatriz ; Blanco, Luis ; Salas, Margarita ; Vega, Miguel de
Issue Date2018
CitationProceedings of the National Academy of Sciences of the United States of America 115: E2921- E2929 (2018)
AbstractMost replicative DNA polymerases (DNAPs) are endowed with a 3′-5′ exonuclease activity to proofread the polymerization errors, governed by four universally conserved aspartate residues belonging to the Exo I, Exo II, and Exo III motifs. These residues coordinate the two metal ions responsible for the hydrolysis of the last phosphodiester bond of the primer strand. Structural alignment of the conserved exonuclease domain of DNAPs from families A, B, and C has allowed us to identify an additional and invariant aspartate, located between motifs Exo II and Exo III. The importance of this aspartate has been assessed by site-directed mutagenesis at the corresponding Asp of the family B ϕ29 DNAP. Substitution of this residue by either glutamate or alanine severely impaired the catalytic efficiency of the 3′-5′ exonuclease activity, both on ssDNA and dsDNA. The polymerization activity of these mutants was also affected due to a defective translocation following nucleotide incorporation. Alanine substitution for the homologous Asp in family A T7 DNAP showed essentially the same phenotype as ϕ29 DNAP mutant D121A. This functional conservation, together with a close inspection of ϕ29 DNAP/DNA complexes, led us to conclude a pivotal role for this aspartate in orchestrating the network of interactions required during internal proofreading of misinserted nucleotides.
Identifiersdoi: 10.1073/pnas.1718787115
issn: 1091-6490
Appears in Collections:(IQFR) Artículos
(CBM) Artículos
Files in This Item:
File Description SizeFormat 
accesoRestringido.pdf15,38 kBAdobe PDFThumbnail
Show full item record
Review this work

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.