A very special protein synthesis machinery

September 13, 2018

Ribosomes are among the most important molecular machines within the cell that hardly changed in the course of evolution. Their function is to read copies of our genes, or building plans, and to translate them into proteins.

Research groups from ETH Zürich and the University of Bern, with financial support by the Swiss National Science Foundation, used electron cryo microscopy in order to obtain the atomic-resolution structure of a very unusual ribosome present in the mitochondria of Trypanosoma brucei, the unicellular parasite that causes sleeping sickness. Their study appeared in the latest issue of Science.

Mitochondria are organelles that can be found in each eukaryotic cell. They are the power plants of the cell and contain their own mitochondrial ribosomes (mitoribosomes). They produce a number of proteins that are essential for these power plants. The mitoribosomes of trypanosomes have the same basic function as ribosomes from other organisms, however, they are specialized for the biology of trypanosomes and their structure deviates substantially.

All ribosomes are composed of two types of components; ribonucleic acid (RNA) and proteins. Intriguingly, the researchers found that mitoribosomes of trypanosomes are larger than any other ribosomes, including the ones found in humans. "The mitoribosomes of trypanosomes are primarily build up by proteins, whereas the structure of other ribosomes is dominated by RNA. Consequently, in trypanosomal mitoribosomes, proteins took over the architectural role of the RNA building blocks", says ETH professor Nenad Ban. In analogy, a small wooden house would differ from a big concrete construction, but both would need a roof, stairs, windows and so on.

"Furthermore, the comparison between the protein-dominated mitoribosomes of trypanosomes with the RNA-dominated ribosomes of other organisms allows us to better understand the most basic functional elements and building blocks shared between all ribosomes", Prof. Ban explains.

Trypanosomes are not only an important model system for basic research, but they are also of considerable medical relevance since they cause sleeping sickness, a fatal disease in humans if left untreated. The mitoribosomes are essential for the survival of trypanosomes. As their structure deviates substantially from human ribosomes, they represent a promising drug target to potentially treat sleeping sickness. Comparison between the structures of human and trypanosomal mitochondrial ribosomes could be useful for the identification of selective inhibitors to treat diseases caused by trypanosomes.
-end-
Reference

Ramrath DJF, Niemann M, Leibundgut M, Bieri P, Prange C, Horn EK, Leitner A, Boehringer D, Schneider A, Ban N. Evolutionary shift towards protein-based architecture in trypanosomal mitochondrial ribosomes. Science, published online 13th Sept 2018.

ETH Zurich

Related Proteins Articles from Brightsurf:

New understanding of how proteins operate
A ground-breaking discovery by Centenary Institute scientists has provided new understanding as to the nature of proteins and how they exist and operate in the human body.

Finding a handle to bag the right proteins
A method that lights up tags attached to selected proteins can help to purify the proteins from a mixed protein pool.

Designing vaccines from artificial proteins
EPFL scientists have developed a new computational approach to create artificial proteins, which showed promising results in vivo as functional vaccines.

New method to monitor Alzheimer's proteins
IBS-CINAP research team has reported a new method to identify the aggregation state of amyloid beta (Aβ) proteins in solution.

Composing new proteins with artificial intelligence
Scientists have long studied how to improve proteins or design new ones.

Hero proteins are here to save other proteins
Researchers at the University of Tokyo have discovered a new group of proteins, remarkable for their unusual shape and abilities to protect against protein clumps associated with neurodegenerative diseases in lab experiments.

Designer proteins
David Baker, Professor of Biochemistry at the University of Washington to speak at the AAAS 2020 session, 'Synthetic Biology: Digital Design of Living Systems.' Prof.

Gone fishin' -- for proteins
Casting lines into human cells to snag proteins, a team of Montreal researchers has solved a 20-year-old mystery of cell biology.

Coupled proteins
Researchers from Heidelberg University and Sendai University in Japan used new biotechnological methods to study how human cells react to and further process external signals.

Understanding the power of honey through its proteins
Honey is a culinary staple that can be found in kitchens around the world.

Read More: Proteins News and Proteins 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.