Vault structure
(a single protein in red)
at 3.5 Angstrom Resolution”
H Tanaka et al., Science,
323: 384–388 (2009).
They’re called “vaults”. They‘re in our cells, and in those of every* plant, animal, and fungus. Like ribosomes, they’re atomically precise self-assembled structures made of protein and RNA, but they’re big and hollow, large enough to pack many ribosomes inside. They’re relatively simple and symmetric: A vault consists of two identical halves, each consisting almost entirely of 39 identical copies of a single, large protein (see figure). The vault structure was recently determined to near-atomic resolution, revealing enough detail to show how the proteins fold and fit together. Looking forward, this information could help protein engineers develop methodologies for designing self-assembling structures for advanced nanotechnology.
* Update: Not quite. A number of journal articles have called them ubiquitous — they are found in organisms as different as human beings and slime molds — yet vaults seem absent from species scattered across the eukaryotes, including some fungi, some plants, and some invertebrates. Highly conserved, except when they’re not.
Vaults are unusual in many ways, but what I find most surprising about them is this:
To this day, no one knows what they do.
See also:
- How to Learn About Everything
- How to Understand Everything (and why)
- Knowledge about Knowledge: The most popular posts in the first year
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Does anyone know what they did? Are they vestigial?
That’s an interesting puzzle.
From your post, I assume they are present in all eukaryotes. I wonder how numerous they are (are they present in higher number in certain species?), and what happens (if anything) when you somehow remove all of them from an otherwise intact cell.
btw, I just finished reading Engines of Creations (I know, I’m late). Great book. I’ll dig deeper in your more recent papers, but it almost left me wanting for a new afterword (more recent than the 1990 one). Have you published something like that since?
@ Don — A mutation or two would be enough to halt vault production, so they must have an ongoing function in cells, yet to quote from the recent Science paper, “the cellular function remains unclear”. From what I’ve read elsewhere, studying them wasn’t fashionable until relatively recently, with the discovery of a nebulous link to the resistance of some cancer cells to cytotoxic drugs.
@ Michael — A recent afterword (though under a different label) is in Engines 2.0, an e-book linked near the top of this page at E-drexler.com. I’ve been intending to write something similar and post it with the html version.
hello,
i am stephen Bauer at shaker junior high. I am researching you for my project and wanted to know if you could help me out with getting some information.
thank you,
Stephen Bauer
There’s a program called Folding at Home and it helps universities use your computer and many others instead of a super computer to help undertsand folding proteins at a faster rate. Look it up, I think it has a lot to do with this sort of stuff. There’s no harm in using the program, just turn it on when your not using your computer.
Heh, maybe God’s just showing off a bit :D
@ Christine — Thanks for mentioning Folding@home, which is helping protein scientists understand the process of folding. I’d like to mention another program, Rosetta@home, that is helping protein scientists and engineers predict and design protein folds. It runs the same way, on software that makes it easy to switch among @home projects.
The approaches are very different. Folding@home follows the dynamics of a protein chain as it folds, while Rosetta@home compares alternative results (not the process) of folding one chain in many alternative ways. For fold prediction and design, this is enormously more effective. I’ve contributed quite a bit of my own machine time. It contributes to knowledge that is directly applicable to promising approaches for engineering atomically precise nanosystems. The Baker lab is behind this project, and they are arguable the leading group in the area.
Any relation to chaperonins, perhaps? Even after graduating with a strong BS in Biology, I am still disenfranchised to learn how little we know about what we believe and teach. Mitochondria may be the powerhouse, ATP may be the fuel, but we still don’t know why or how. Even astrioles, cytomeres, and their interactions with the cytoskeleton and microtubule pathways are hardly understood. While we constantly make progress, our certainty in our uncertainty is often disheartening and disinspiriring (<- I am coining that term. Fornicate the spellcheck).
I am working on vaults for my undergraduate research. I (along with several other scientists) am trying to take advangage of the vault’s encapsulation ablilities to deliver theriputic compounds to specific tissues. Hopefully the vault will be used as a drug container in novel therapies.
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