A small protein in bacteria overlooked up to now

January 29, 2021

The biological process of photosynthesis is found at the beginning of nearly all food chains. It produces oxygen to breathe and provides the energetic foundation for using biotechnological processes to synthesize biofuels and chemical feedstock. Therefore, researchers are particularly interested in rapidly growing cyanobacteria. These organisms use light as an energy source and can carry out photosynthesis, similar to plants. However, the required photosynthetic protein complexes bind many nutrients. Vanessa Krauspe and Prof. Dr. Wolfgang Hess from the working group for Genetics & Experimental Bioinformatics of the Faculty of Biology of the University of Freiburg and their collaborators have discovered the small, previously unknown protein NblD, which is involved in the recycling of these nutrients. The researchers are presenting their new findings in the specialist journal PNAS.

In addition to the pigment chlorophyll, cyanobacteria use for photosynthesis frequently also phycobilisomes, complexes consisting of proteins and another class of tetrapyrrole pigments, which are considered as the most effective light-harvesting structures found in nature. However, using phycobilisomes is costly for the cell as they bind a huge amount of nutrients in their macromolecular structures - nitrogen in particular. In order to recycle these nutrients under scarcity conditions, for example under conditions of insufficient nitrogen supplies, the cyanobacteria have sophisticated genetic programs which, among scientists, are actually considered to be well-examined.

In a new approach, aiming at taking a closer look at especially small genes and proteins, the team at the University of Freiburg has been able to characterize NblD. It is a previously unknown small protein with high-affinity, meaning it rapidly forms bonds. NblD binds specifically to what is known as the phycocyanin beta-subunit of the phycobilosome. Through this process cyanobacterial cells receive special mechanisms to handle potentially dangerous intermediate products that occur during the recycling of the phycobilisomes. Hess says, "The results illustrate the fact that especially small genes and proteins have been neglected hitherto and deserve a closer look."
-end-
The team of Krauspe and Hess accomplished the new findings in cooperation with Prof. Dr. Oliver Schilling of the University Medical Center Freiburg, Prof. Dr. Boris Maček of the University of Tübingen, and Prof. Dr. Nicole Frankenberg-Dinkel of the Technical University of Kaiserslautern.

The work has been supported by the German Research Foundation (DFG) within the priority program (SPP) 2002 "Small Proteins in Prokaryotes, an Unexplored World", the research training group (GRK) 2344 "MeInBio - BioInMe: Exploration of spatio-temporal dynamics of gene regulation using high-throughput and high-resolution methods", as well as the research group (FOR) 2816 "The Autotrophy-Heterotrophy Switch in Cyanobacteria: Coherent Decision-Making at Multiple Regulatory Layers (SCyCode)."

Original publication: Krauspe V., Fahrner M., Spät P., Macek B., Schilling O., Hess W.R. (2021): Discovery of a small protein factor involved in the coordinated degradation of phycobilisomes in cyanobacteria. In: Proc Natl Acad Sci USA, Vol. 118, No. 5 e2012277118; DOI: 10.1073/pnas.2012277118.

Contact: Institute of Biology III
Faculty of Biology
University of Freiburg

University of Freiburg

Related Photosynthesis Articles from Brightsurf:

During COVID, scientists turn to computers to understand C4 photosynthesis
When COVID closed down their lab, a team from the University of Essex turned to computational approaches to understand what makes some plants better adapted to transform light and carbon dioxide into yield through photosynthesis.

E. coli bacteria offer path to improving photosynthesis
Cornell University scientists have engineered a key plant enzyme and introduced it in Escherichia coli bacteria in order to create an optimal experimental environment for studying how to speed up photosynthesis, a holy grail for improving crop yields.

Showtime for photosynthesis
Using a unique combination of nanoscale imaging and chemical analysis, an international team of researchers has revealed a key step in the molecular mechanism behind the water splitting reaction of photosynthesis, a finding that could help inform the design of renewable energy technology.

Photosynthesis in a droplet
Researchers develop an artificial chloroplast.

Even bacteria need their space: Squished cells may shut down photosynthesis
Introverts take heart: When cells, like some people, get too squished, they can go into defense mode, even shutting down photosynthesis.

Marine cyanobacteria do not survive solely on photosynthesis
The University of Cordoba published a study in a journal from the Nature group that supports the idea that marine cyanobacteria also incorporate organic compounds from the environment.

Photosynthesis -- living laboratories
Ludwig-Maximilians-Universitaet (LMU) in Munich biologists Marcel Dann and Dario Leister have demonstrated for the first time that cyanobacteria and plants employ similar mechanisms and key proteins to regulate cyclic electron flow during photosynthesis.

Photosynthesis seen in a new light by rapid X-ray pulses
In a new study, led by Petra Fromme and Nadia Zatsepin at the Biodesign Center for Applied Structural Discovery, the School of Molecular Sciences and the Department of Physics at ASU, researchers investigated the structure of Photosystem I (PSI) with ultrashort X-ray pulses at the European X-ray Free Electron Laser (EuXFEL), located in Hamburg, Germany.

Photosynthesis olympics: can the best wheat varieties be even better?
Scientists have put elite wheat varieties through a sort of 'Photosynthesis Olympics' to find which varieties have the best performing photosynthesis.

Strange bacteria hint at ancient origin of photosynthesis
Structures inside rare bacteria are similar to those that power photosynthesis in plants today, suggesting the process is older than assumed.

Read More: Photosynthesis News and Photosynthesis Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.