Biochemical characterization and mutational analysis of the NurA protein from the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5

Copyright © 2024 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved..

Archaeal NurA protein plays a key role in producing 3'-single stranded DNA used for homologous recombination repair, together with HerA, Mre11, and Rad50. Herein, we describe biochemical characteristics and roles of key amino acid residues of the NurA protein from the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5 (Tba-NurA). Tba-NurA possesses 5'-3' exonuclease activity for degrading DNA, displaying maximum efficiency at 45 °C-65 °C and at pH 8.0 in the presence of Mn2+. The thermostable Tba-NurA also possesses endonuclease activity capable of nicking plasmid DNA and circular ssDNA. Mutational data demonstrate that residue D49 of Tba-NurA is essential for exonuclease activity and is involved in binding ssDNA since the D49A mutant lacked exonuclease activity and reduced ssDNA binding. The R96A and R129A mutants had no detectable dsDNA binding, suggesting that residues R96 and R129 are important for binding dsDNA. The abolished degradation activity and reduced dsDNA binding of the D120A mutant suggest that residue D120 is essential for degradation activity and dsDNA binding. Additionally, residues Y392 and H400 are important for exonuclease activity since these mutations resulted in exonuclease activity loss. To our knowledge, it is the first report on biochemical characterization and mutational analysis of the NurA protein from Thermococcus.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - year:2024

Enthalten in:

Research in microbiology - (2024) vom: 24. Feb., Seite 104189

Sprache:

Englisch

Beteiligte Personen:

Ma, Guangyu [VerfasserIn]
Lin, Tan [VerfasserIn]
Cao, Peng [VerfasserIn]
Oger, Philippe [VerfasserIn]
Dong, Kunming [VerfasserIn]
Miao, Li [VerfasserIn]
Zhang, Likui [VerfasserIn]

Links:

Volltext

Themen:

DNA repair
Endonuclease
Exonuclease
Hyperthermophilic archaea
Journal Article
NurA protein

Anmerkungen:

Date Revised 29.02.2024

published: Print-Electronic

Citation Status Publisher

doi:

10.1016/j.resmic.2024.104189

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM368929825