Your new experience awaits. Try the new design now and help us make it even better

ORIGINAL RESEARCH article

Front. Microbiol.

Sec. Extreme Microbiology

Volume 16 - 2025 | doi: 10.3389/fmicb.2025.1572269

Archaeal LOV domains from Lake Diamante: first functional characterization of a halo-adapted photoreceptor

Provisionally accepted
Valle LorenaValle Lorena1,2Yonathan J CoronelYonathan J Coronel1,2Guillermina E BravoGuillermina E Bravo2Joaquin A DíazJoaquin A Díaz2Virginia Helena AlbarracínVirginia Helena Albarracín3,4Maria E FariasMaria E Farias5Ines AbatedagaInes Abatedaga1*
  • 1CONICET Institute of Bionanotechnology of NOA (INBIONATEC), Santiago del Estero, Santiago del Estero, Argentina
  • 2National University of Santiago del Estero, Santiago del Estero, Santiago del Estero, Argentina
  • 3Universidad Nacional de Tucumán, San Miguel de Tucumán, Tucumán, Argentina
  • 4CONICET CCT-NOA SUR, San Miguel de Tucuman, Argentina
  • 5PUNABIO S.A., San Pablo, Tucumán, Argentina

The final, formatted version of the article will be published soon.

Select one of your emails

You have multiple emails registered with Frontiers:

Notify me on publication

Please enter your email address:

If you already have an account, please login

You don't have a Frontiers account ? You can register here

High-altitude Andean lakes (HAALs) represent polyextreme environments where diverse photoinduced processes have been documented. In this study, we investigated Light-Oxygen-Voltage (LOV) photoreceptors and identified 28 archaeal sequences from Lake Diamante, which were classified into two major groups (A and B), with three outliers showing unique structural features. Analysis of these sequences and their 3D models revealed hallmark adaptations to halophilic environments, including an abundance of surface acidic residues, an increased prevalence of arginine over lysine, and a greater density of salt bridges. The heterologous expression of a representative LOV domain, ALovD-1, demonstrated conserved photophysics between its dark-and light-adapted states, which was consistent with the slow cycling type. Importantly, ALovD-1 exhibited remarkable halophilic characteristics, maintaining photocycling functionality at salt concentrations as high as 3 M monovalent salts. This ability can be attributed to discrete structural changes, allowing adjustments in flavin interactions within its cavity under varying ionic strengths. Mutational studies of key residues (Y30F and Y48F) highlighted their roles in modulating flavin photophysic and revealed a stabilizing function for Y48 at low salt concentrations. These findings mark the first functional characterization of a canonical archaeal LOV domain, expanding our understanding of light sensing and protein adaptation in extremophiles.

Keywords: LOV photoreceptor1, Archaea2, flavoprotein3, extremophiles4, halo-adapted protein5

Received: 06 Feb 2025; Accepted: 26 May 2025.

Copyright: © 2025 Lorena, Coronel, Bravo, Díaz, Albarracín, Farias and Abatedaga. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Ines Abatedaga, CONICET Institute of Bionanotechnology of NOA (INBIONATEC), Santiago del Estero, 4000, Santiago del Estero, Argentina

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

Supplementary Material