TY - JOUR

T1 - Multifaceted photoreceptor compositions in dual phototrophic systems – A genomic analysis

AU - Ihalainen, Janne A.

AU - Dogan, Batuhan

AU - Kurttila, Moona

AU - Zeng, Yonghui

AU - van Elsas, Jan Dirk

AU - Nissinen, Riitta

N1 - Publisher Copyright: © 2023 The Author(s)

PY - 2024

Y1 - 2024

N2 - For microbes and their hosts, sensing of external cues is essential for their survival. For example, in the case of plant associated microbes, the light absorbing pigment composition of the plant as well as the ambient light conditions determine the well-being of the microbe. In addition to light sensing, some microbes can utilize xanthorhodopsin based proton pumps and bacterial photosynthetic complexes that work in parallel for energy production. They are called dual phototrophic systems. Light sensing requirements in these type of systems are obviously demanding. In nature, the photosensing machinery follows mainly the same composition in all organisms. However, the specific role of each photosensor in specific light conditions is elusive. In this study, we provide an overall picture of photosensors present in dual phototrophic systems. We compare the genomes of the photosensor proteins from dual phototrophs to those from similar microbes with ”single” phototrophicity or microbes without phototrophicity. We find that the dual phototrophic bacteria obtain a larger variety of photosensors than their light inactive counterparts. Their rich domain composition and functional repertoire remains similar across all microbial photosensors. Our study calls further investigations of this particular group of bacteria. This includes protein specific biophysical characterization in vitro, microbiological studies, as well as clarification of the ecological meaning of their host microbial interactions.

AB - For microbes and their hosts, sensing of external cues is essential for their survival. For example, in the case of plant associated microbes, the light absorbing pigment composition of the plant as well as the ambient light conditions determine the well-being of the microbe. In addition to light sensing, some microbes can utilize xanthorhodopsin based proton pumps and bacterial photosynthetic complexes that work in parallel for energy production. They are called dual phototrophic systems. Light sensing requirements in these type of systems are obviously demanding. In nature, the photosensing machinery follows mainly the same composition in all organisms. However, the specific role of each photosensor in specific light conditions is elusive. In this study, we provide an overall picture of photosensors present in dual phototrophic systems. We compare the genomes of the photosensor proteins from dual phototrophs to those from similar microbes with ”single” phototrophicity or microbes without phototrophicity. We find that the dual phototrophic bacteria obtain a larger variety of photosensors than their light inactive counterparts. Their rich domain composition and functional repertoire remains similar across all microbial photosensors. Our study calls further investigations of this particular group of bacteria. This includes protein specific biophysical characterization in vitro, microbiological studies, as well as clarification of the ecological meaning of their host microbial interactions.

KW - aerobic anoxygenic phototrophy

KW - dual phototrophy

KW - photosensor

KW - rhodopsin

U2 - 10.1016/j.jmb.2023.168412

DO - 10.1016/j.jmb.2023.168412

M3 - Journal article

C2 - 38135178

AN - SCOPUS:85182456317

VL - 436

JO - Journal of Molecular Biology

JF - Journal of Molecular Biology

SN - 0022-2836

IS - 5

M1 - 168412

ER -