Light-induced structural changes during the signaling mechanism of a full-length bacteriophytochrome (Póster)

LISANDRO H. OTERO; SABRINA FOSCALDI; GIULIANO T. ANTELO; GERMÁN L. ROSANO; SERENA SIRIGU; SEBASTIÁN KLINKE; LUCAS A. DEFELIPE; MAXIMILIANO SÁNCHEZ-LAMAS; GIOVANNI BATTOCCHIO; VALERIA CONFORTE; ADRIAN A. VOJNOV; LEONARD CHAVAS; FERNANDO A. GOLDBAUM; MARÍA A. MROGINSKI; JIMENA RINALDI; HERNÁN R. BONOMI

Evento online debido a la pandemia de coronavirus

Conferencia; EMBL Conference "Bringing molecular structure to life: 50 years of the PDB"; 2021

European Molecular Biology Laboratory (EMBL)

Light sensing allows organisms to adapt to constantly changing environmental factors. Phytochromes constitute a major superfamily of light-sensing proteins that are reversibly photoconverted between a red-absorbing (Pr) and a far-red-absorbing (Pfr) state. Bacteriophytochromes (BphPs) are found among photosynthetic and non-photosynthetic bacteria, including pathogens. To date, several BphPs have been biophysically characterized. However, it is still not fully understood how structural changes are propagated from the photosensory module (PSM) to the output module (OM) during the signal transduction event. Herein, we present crystallographic structures from the plant pathogen Xanthomonas campestris virulence regulator bacteriophytochrome XccBphP, including two full-length proteins, in the Pr and Pfr states. The structural findings, combined with mutational, biochemical and computational studies, allow us to describe the signaling mechanism of a full-length bacterial phytochrome at the atomic level, from the isomerization of the chromophore and the beta-sheet/alpha-helix tongue transition to the remodeling of the quaternary assembly of the protein. This work contributes to understand the light-induced structural changes propagated from the PSM to the OM in phytochrome signaling.