In all present-day organisms, information encoded in DNA, the genetic material of the cell, is converted via an RNA intermediate into proteins, the molecular machines of the cell. However, evidence suggests that in a distant evolutionary past our single-celled ancestors used only RNA for both genetic information storage and metabolism. A cornerstone of this “RNA world” would have been an RNA able to replicate itself.
Mitochondria are organelles within eukaryotic cells that likely evolved from an ancient bacterium that was engulfed by a primordial eukaryote. Within mitochondria, mitochondrial ribosomes (mitoribosomes) synthesise a subset of essential proteins encoded by the mitochondrial genome.
Every minute, cells make millions of new proteins which must be transported to the correct location, folded, modified and assembled with other proteins in order to function properly. Failure at any of these maturation steps can reduce protein function and lead to the accumulation of aberrant protein intermediates, resulting in disease.
The state of the immune system has effects on brain function, but despite suggestions that immunoregulators can affect people’s mood and behaviour, we are only beginning to understand how these two major body systems interact. The contributions of a neuron to circuit activity and behaviour depend on its responsiveness to upstream inputs, and its ability to drive downstream outputs.
The spliceosome is a molecular machine, which together with RNA polymerases and ribosomes plays a critical role in basic gene expression. Research by Kiyoshi Nagai’s group in the LMB’s Structural Studies Division, has previously revealed the structure of the spliceosome in a fully active, substrate-bound state, immediately after its first catalytic reaction. The group has now expanded upon this work revealing the near-atomic level structure of the spliceosome just before mRNA formation.