In a collaborative study involving the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), the University of Tokyo, RIKEN, Okayama University, and the Japan Science and Technology Agency (JST), a new light-utilization system in cyanobacteria has been discovered. This system, named CyanoRhodopsin-II (CyR-II), provides insight into how cyanobacteria adapt to various environments.
Environmental Adaptation Through CyR-II: Two Distinct Light-Utilization Mechanisms
Cyanobacteria, recognized as one of the oldest photosynthetic organisms on Earth, inhabit a variety of environments. Through a joint study by JAMSTEC, the University of Tokyo, RIKEN, Okayama University, and JST, researchers discovered a new mechanism in cyanobacteria for utilizing light, termed CyanoRhodopsin-II (CyR-II). This CyR-II system has the ability to absorb both green and yellow light, potentially aiding cyanobacteria in adapting to different environmental conditions.
While the photosynthetic process in cyanobacteria was previously known, the system by which they use light through proteins called rhodopsins remained largely unexplored. This newly identified CyR-II system, a type of microbial rhodopsin, has been observed particularly in mangrove and coastal regions, suggesting that it may play a significant role in cyanobacteria’s adaptation to specific environments. This finding indicates a possible evolutionary advancement in cyanobacteria’s energy utilization methods beyond photosynthesis.
CyR-II is notable for its selective utilization of either green or yellow light. By analyzing the structure of CyR-II, researchers have pinpointed minor structural changes that account for its ability to absorb different wavelengths of light. This discovery provides a crucial insight into how cyanobacteria have evolved a diverse array of light-utilization mechanisms, enabling them to adapt to different ecological niches over time.
This research highlights a novel light-utilization strategy in the evolution of cyanobacteria and is anticipated to advance our understanding of both marine and terrestrial ecosystems.