ALovD-1: First structural and functional characterization of an archaeal Cys containing LOV photoreceptor isolated from a local saline lake

VALLE, LORENA; CORONEL YONATHAN JAVIER; DIAZ, JOAQUÍN AUGUSTO; BRAVO, EUGENIA GUILLERMINA; VIRGINIA H. ALBARRACÍN; FARIAS, MARIA EUGENIA; ABATEDAGA, INES

Córdoba

Congreso; SAB 2023-LI Reunión Anual de la Sociedad Argentina de Biofísica; 2023

Sociedad Argentina de Biofísica

High-Altitude Andean Lakes have been described as polyextremophilic environmentsand plenty of photoinduced processes have been documented. Lake Diamante'smetagenomic taxonomical analysis revealed mostly members from the Archaeadomain of life. In this context, we searched for Light Oxygen Voltage (LOV)photoreceptors with 24 of these Archaeal sequences being part of two major groups (Aand B) except for 3 domains that did not group even with the reference sequencesincluded for the analysis. Several signatures of halo-adapted proteins were foundamongst archaeal sequences, i.e. abundance of acidic residues on the surface, anincreased number of arginine residues at the expense of lysines, and a multiplicity ofsalt bridges. Heterologous expression of one of these domains, ALovD-1, showed thatthe photophysics for the dark and the light-adapted states was fairly conserved. Herewe present proof that suggests it behaves as a moderate halophilic photoreceptorsince it conserves activity from 0.5 M to 2 M of monovalent salt. This is the firstcysteine-containing Archaeal LOV domain characterized in the literature to ourknowledge.