This approach is pretty much like the TED approach from a few years back. As far as I remember there wasn’t a ridiculous amount of fold diversity there either. It turns out evolution isn’t averse to a bit of liberal protein plagiarism.

https://www.science.org/doi/10.1126/science.adq4946

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gilleain 38 minutes ago | parent | next [-]

They found "several thousand" novel folds? I had remembered that there were around 1000:

https://pmc.ncbi.nlm.nih.gov/articles/PMC7072414/

Oh ok, I misremembered:

"This review has focused only on small fragments of fold space with examples given for folds generated from a single secondary structure string consisting of around ten SSEs. Even in this small corner, the number of possible folds, under the current constraints, is of the order of 1000"

	▲	hirenj 15 minutes ago \| parent [-]
		I think there was a Twitter/Bluesky thread on the results from adding all the predicted folds from metagenomics too, and not ending up with many new clusters. If this continues to hold true as we keep looking at stuff, I will be relieved that at least natural protein folds and domains has a limited (tractable) solution space. All we need to do now is annotate the variation of these couple of thousands of fold variants. Challenging, but at least a bounded problem.

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jeejay1 an hour ago | parent | prev [-]

What plagiarism even means in context of proteins? That one protein steals a fold of another protein without giving proper credit to it?

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gilleain 35 minutes ago | parent [-]

I understood it as metaphor - just that evolutionarily distant sequences can adopt the same (or very similar) folds because there are only a limited number of stable, accessible folds that are possible.

	▲	hirenj 4 minutes ago \| parent [-]
		Yes, that is exactly what I meant! Here’s an experiment to try: Frances Arnold got a nobel prize for work related to directed evolution. However, we know evolution is limited by the tools available to it as you mention. If we add random chaperones and co-factors to bacteria that we know other organisms use, can we push evolution outside of the known fold space? Is the limited fold space an absolute limit or the “accessible” limit?