Marine cyanobacteria (blue-green algae) are a major contributor to the global carbon cycle and form the basis of the food web in many of the world’s oceans. They only need sunlight, carbon dioxide and some essential elements, including metals, to stay alive. However, little is known about whether and how cyanobacteria use or regulate zinc, an element often considered essential for life.
A four-member interdisciplinary research team from the University of Warwick has identified a remarkably efficient regulatory network that controls zinc accumulation in the open ocean cyanobacterium Synechococcus.
The discovery is detailed in a paper published today in Nature Chemical BiologyLink opens in a new window†
This network allows Synechococcus to vary their internal zinc levels by more than two orders of magnitude, and relies on a zinc uptake regulating protein (Zur) that can detect zinc and react accordingly.
Uniquely, this sensor protein activates a bacterial metallothionein (zinc-binding protein) which, along with highly efficient absorption systems, is responsible for this organism’s extraordinary ability to accumulate zinc.
Professor Claudia Blindauer from Warwick’s Department of Chemistry commented: “Our findings indicate that zinc is an essential element for marine cyanobacteria. Their ability to store zinc can facilitate better absorption of phosphorus, a macronutrient that is extremely scarce in many regions of the world’s oceans. Zinc may also be needed for efficient carbon fixation.”
dr. Alevtina Mikhaylina from Warwick’s School of Life Sciences noted: “These features, which have not yet been reported for any other bacteria, likely contribute to the wide ecological distribution of Synechococcus across the global oceans. We hope our findings will be of interest to a wide range of researchers, from biochemists (particularly trace metal and bio-inorganic chemists), structural biologists and molecular biologists to biogeochemists, microbial ecologists and oceanographers.”
dr. Rachael Wilkinson, of Swansea University Medical School, and Professor Vilmos Fülöp, of Warwick’s School of Life Sciences, added: “As part of an interdisciplinary project, the structure of the Zur protein has provided mechanical insights into how it is central role in regulatory zinc homeostasis in marine cyanobacteria.”
dr. James Coverdale, of the Institute of Clinical Sciences, University of Birmingham, commented: “By working at the interfaces of microbiology, analytical, structural and biological chemistry, our interdisciplinary team has expanded our understanding of how inorganic chemistry affects life in our oceans. significantly improved.”
Professor Dave Scanlan, from Warwick’s School of Life Sciences, added: “The oceans are the somewhat overlooked ‘lungs’ of our planet – every other breath we take is oxygen evolved from marine systems, while about the Half of the carbon dioxide is trapped in biomass on Earth.Marine cyanobacteria are key players in the Earth’s “lungs” and this manuscript reveals a novel aspect of their biology, namely the ability to superbly regulate zinc homeostasis, a trait that undoubtedly contributed to their ability to perform these important planetary functions.”
- “A single sensor controls large variations in zinc quota in a marine cyanobacterium” Alevtina Mikhaylina, Amira Z. Ksibe, Rachael C. Wilkinson, James PC Coverdale, Vilmos Fülöp, David J. Scanlan, Claudia A. Blindauer, published in Nature Chemical Biology ( 2022)
- Available at: https://www.nature.com/articles/s41589-022-01051-1
- This work was supported by the Biotechnology and Biological Sciences Research Council (grant reference BB/M003523/1) and the Natural Environment Research Council (grant reference NE/I00985X/1). Some of the equipment used in this study was obtained through Birmingham Science City with support from Advantage West Midlands and the European Regional Development Fund.
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