Redox controls RecA protein activity via reversible oxidation of its methionine residues

Camille Henry (1, 2) , Laurent Loiseau (1) , Alexandra Vergnes (1) , Didier Vertommen (3) , Angela Mérida-Floriano (4) , Sindhu Chitteni-Pattu (2) , Elizabeth Wood (2) , Josep Casadesús (4) , Michael Cox (2) , Frédéric Barras (1, 5) , Benjamin Ezraty (1)

1 LCB - Laboratoire de chimie bactérienne
2 University of Wisconsin-Madison
3 UCL - Université Catholique de Louvain = Catholic University of Louvain
4 Universidad de Sevilla = University of Seville
5 SAMe - Adaptation au stress et Métabolisme chez les entérobactéries - Stress adaptation and metabolism in enterobacteria

Reactive oxygen species (ROS) cause damage to DNA and proteins. Here, we report that the RecA recombinase is itself oxidized by ROS. Genetic and biochemical analyses revealed that oxidation of RecA altered its DNA repair and DNA recombination activities. Mass spectrometry analysis showed that exposure to ROS converted four out of nine Met residues of RecA to methionine sulfoxide. Mimicking oxidation of Met35 by changing it for Gln caused complete loss of function, whereas mimicking oxidation of Met164 resulted in constitutive SOS activation and loss of recombination activity. Yet, all ROS-induced alterations of RecA activity were suppressed by methionine sulfoxide reductases MsrA and MsrB. These findings indicate that under oxidative stress MsrA/B is needed for RecA homeostasis control. The implication is that, besides damaging DNA structure directly, ROS prevent repair of DNA damage by hampering RecA activity.

Domaines: Sciences du Vivant [q-bio]

Camille Henry, Laurent Loiseau, Alexandra Vergnes, Didier Vertommen, Angela Mérida-Floriano, et al.. Redox controls RecA protein activity via reversible oxidation of its methionine residues. eLife, 2021, 10, ⟨10.7554/eLife.63747⟩. ⟨hal-03216664⟩