Electron cryo-microscopy visualisation of bioenergetic complexes.
Our research group investigates the fundamental question of how proteins are synthesized, folded and assembled into functional multicomponent membrane complexes that drive the cellular energy production.
Living cells ultimately depend on the conversion of energy derived from foodstuff and light into the chemical form of energy. This crucial bioenergetic step is performed in the membrane systems of mitochondria and chloroplasts. Each one of these organelle types has developed dedicated ribosomes that have diverged from the cytoplasmic counterparts. While mitoribosomes synthesize proteins involved in the oxidative phosphorylation, chlororibosomes produce components driving the pohotosynthetic reactions through pigment-protein units. To dissect the mechanism and dynamics of translation, membrane insertion and bioenergetics in organelles, we use cryo-EM.
Our group determined cryo-EM structures of the human mitoribosome with mRNA, tRNAs and translation activators in 8 different functional states, as well as its assembly intermediates. It revealed unique mechanisms of mRNA binding, tRNA translocation and assembly regulation. We also determined structures of the chlororibosome with translation factors that revealed divarication of the exit tunnel and experimental evidence for convergent evolution of ribosomes from chloroplasts and mitochondria.
These studies showed that protein synthesis machineries in organelles have adopted intricate compositions and unique tasks, adding incredible complexity to the records. The achieved understanding of the architecture of these specialized systems provides now a framework to study even more sophisticated questions regarding the assembly and evolution mechanisms of the critical bioenergetic membranes that fuel life.
Shintaro Aibara, Postdoc
Juni Andréll, Researcher
Yuzuru Itoh, Postdoc
Narges Mortezaei, Postdoc
Alexander Muhleip, Postdoc
Laura Orellana, Postdoc
Annemarie Perez Boerema, Student
Andre Rosa, Student
Vivek Singh, Student
Victor Tobiasson, Student
Perez Boerema A., Aibara S., Paul B., Tobiasson V., Kimanius D., Forsberg B. O., Wallden K., Lindahl E. and Amunts A. (2018). Structure of the chloroplast ribosome with chl-RRF and hibernation-promoting factor. Nature Plants in press
Forsberg B. O., Aibara S., Kimanius D., Paul B., Lindahl E. and Amunts A. (2017). Cryo-EM reconstruction of the chlororibosome to 3,2 Å resolution within 24h. International Union of Crystallography journal 4, 723-727.
Brown A., Rathore S., Kimanius D., Aibara S., Bai X., Rorbach J., Amunts A.* and Ramakrishnan V.* (2017). Structures of the human mitochondrial ribosome in native states of assembly. Nature Structural and Molecular Biology 24, 866-869.
Matzov D., Aibara S., Basu A., Zimmerman E., Bashan A., Yap M-N.F., Amunts A.* and Yonath A.* (2017). The cryo-EM structure of hibernating 100S ribosome dimer from pathogenic Staphylococus aureus. Nature comm. 8, 723.
Desai N., Brown A., Amunts A. and Ramakrishnan V. (2017). The structure of the yeast mitochondrial ribosome. Science 355, 528-531.
“Hire very smart people. Leave them alone, but with a tea room to talk. Support them so they have time, & aren’t chasing money.” Max Perutz
If you have new unconvential ideas, please contact Alexey Amunts
Structural Biology discussion group
We gather a discussion group to better understand the current practice of cryo-EM, present the most recent developments and applications to interesting biological problems. The list of upcoming speakers is found here
We encourage everyone to take active part.
Annual Sjöstrand Lecture in Structural Biology
The lecture series is set up in the recognition of Fritiof Sjöstrand’s contribution to the development of structural biology.
Venki Ramakrishnan will give the inaugural Sjöstrand Lecture on Monday 27th August 2018 at 4.00pm in the Biomedicum Lecture Theatre.