Biological complexity: structure of a mitochondrial ribosome (Introduction)

by David Turell , Thursday, February 18, 2021, 21:38 (1162 days ago) @ David Turell

Another article on structure and function:

https://phys.org/news/2021-02-mitochondria-genesis-body-powerhouses.html

"The bulk of energy production in mitochondria takes place in naturally evolved nano-factories incorporated in specialised membranes. These nano-factories consist of proteins cooperatively transporting ions and electrons to generate the chemical energy currency of our bodies which have to be constantly maintained, replaced and duplicated during cell division. To address this, mitochondria have their own protein making machine called the mitoribosome. The first fundamental understanding of how the mitoribosome looks was achieved in 2014.

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"'...this first glimpse into the architecture revealed only a partial picture of a static model. Yet the mitoribosome is a flexible molecular machine that requires the motion of its parts relative to each other in order to work. Therefore, in the current study, the team used the high throughput cryo-EM data acquisition at the electron Bio-Imaging Centre (eBIC) at Diamond to obtain 30 times more data allowing the team to describe conformational changes during the process of protein synthesis and association with the membrane adaptor. eBIC has been a strategic investment from the Wellcome Trust, UKRI's BBSRC and MRC. Being embedded at Diamond, eBIC benefits from amongst other things the well-established user support in place.

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"'Our study exposed the dynamic molecular mechanism that explains how the mitoribosome actually works to form the cellular powerhouse and reveals that the mitoribosome is much more flexible and active than previously thought. The discovery of intrinsic conformational changes represents a gating mechanism of the mitoribosome without similarity in bacterial and cytosolic systems. Together, the data offer a molecular insight into how proteins are synthesized in human mitochondria," adds Alexey Amunts.

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"The most important aspect of Alexey's work is the interaction between mitoribosome and OXA1L and the associated flexibility. The fact that mitoribosome is flexible as such is not novel, but the particular flexibility associated with OXA1L interaction is. This is important for synthesis of membrane proteins, including respiratory chain proteins. Overall, this work significantly widens our understanding how mitoribosome functions. The work by Alexey Amunts lab resolves another mystery about basic biological processes necessary for creating life as we know it."

"The sequencing of the human mitochondrial genome 40 years ago was a turning point in mitochondrial research, postulating a putative specialized mechanism for the synthesis of the mitochondrial transmembrane proteins. Indeed, the discovered gating mechanism of the human mitoribosome represents a unique occurrence. Therefore, the structural data offer a fundamental understanding into how bioenergetic proteins are synthesized in our body".

Comment: The real point to me is that the mitochondria are so complex new study techniques have to be invented just to study them. Designed, not by chance development .