Highly sophisticated and common to all organisms, ribosomes – the tiny machines that make proteins in cells – are fundamental to life and are one of the most ancient cellular players. Their job is so critical that their structure and function are consistent across all life-forms on Earth, and some portions have even been found to be identical in all organisms examined so far. Needless to say, they’re a pretty big deal. And amazingly, scientists have just managed to create one in the lab.
But that’s not even the most exciting part – the synthetic nanofactory even worked inside living cells and didn’t interfere with the native protein-making machinery. What’s more, it did a remarkably good job, functioning almost as well as the real thing. This could mean that in the future, scientists might be able to use these designer machines to create molecules of interest, such as therapeutic substances.
To recreate these protein-making factories, rather than attempting to make a carbon copy of the native structures found inside cells, scientists from the University of Illinois at Chicago and Northwestern University actually added a new feature not found in nature. Normally, when cells need to make a protein, DNA first gets transcribed into a blueprint called messenger RNA (mRNA). This is then fed through the ribosome, a functional unit made up of two constituent parts – a small and a large subunit – which together translate the instructions contained within the mRNA in order to string together the protein building blocks.
When this process is finished, the subunits go their separate ways, ready to come back together for round two. But this was a problem for biologists trying to get artificial copies to work inside living cells, as the synthetic versions would partner up with the natural counterparts, interfering with normal protein synthesis and thus harming the cell. To get around this, researchers created artificial ribosomes, dubbed “Ribo-T,” in which the subunits are tethered together and thus inseparable. The scientists were actually skeptical that this would work, since it was long believed that subunit separation was pivotal for the process of protein synthesis.
Remarkably, it seems that this assumption was wrong: Ribo-T retained the functionality of a native ribosome, successfully creating proteins in the test tube, the scientists report in Nature. Moreover, it was even able to act in place of the real thing in bacteria lacking natural ribosomes, churning out enough proteins to keep the microbes alive. Of course, it isn’t as efficient as its natural counterpart, but as The Verge points out, those factories have had billions of years to perfect their role.
Although synthetic ribosomes have actually been made before, they had a limited spectrum of use because they were restricted to certain mRNA sequences. But Ribo-T holds the potential to work on an array of sequences, possibly allowing the synthesis of a wide range of desirable proteins and thus opening up applications in medicine and biomaterials. And on top of that, scientists could use them to enhance our understanding of protein synthesis, possibly taking us a step closer to artificial life, although we are still far from that futuristic stage.