I have for some years now been teaching my undergrad students that virus particles are nanomachines: that is, they are highly sophisticated nanoscale (read: ultramicroscopic) devices whose function is to specifically deliver genetic material into an environment where it can be expressed and replicated, so as to make more virus particles.
Ah, but what’s a von Neumann machine, you ask? Well, I note Wikipedia has the following:
- Self-replicating machines, a class of machines that can replicate themselves
- Universal Constructors, self-replicating cellular automata
- Von Neumann probes, hypothetical space probes capable of self-replication
- Nanorobots capable of self-replication
I especially like the last two – because, as I showed in a previous blog post, I like the idea of virus particles or virions as “inner space craft”. That this neatly marries my recreational and professional reading is no coincidence – because they cross-pollinate one another, in that I get ideas about the nature of viruses from SF, and my virology training informs scenarios I would like to write about. Someday. Soon, possibly. Really. Instead of writing about parallel universes contactable via the internet….
However, there is more to viruses and nanotechnology than phages with contractile tails, whether or not they have been around for billions of years: mimiviruses too have both nanoscale DNA loading and rapid-delivery systems, as previously discussed here.
Although I have a passing fondness for possibly my most successful animation – made from actual EMs, done by Linda Stannard.
So it was with some pleasure I saw recently on YouTube a video labelled “Viruses are nanotechnology (how a virus works)“. I was a little less pleased when a voice confidently announced that “…a virus isn’t alive, people – it’s non-metabolising…”, as if that was the sole and necessary criterion for life. I am at one with another Polish-named person – one Bernard Korzeniewski – in thinking that life is (from MicrobiologyBytes)
“The phenomenon associated with the replication of self-coding informational systems” © E.P. Rybicki, 1996. Incidentally, I find another person with a Polish name has said something very similar, in 2001 – which means it must be true. Bernard Korzeniewski describes life as: “A network of inferior negative feedbacks subordinated to a superior positive feedback.”
See, no mention of metabolism – or even of cells! But what got the hairs on the back of my neck standing up, however, was some of the rest of it – delivered in a smooth, folksy manner, with stunning video footage. Absolute cr@p, most of it: viruses are too complicated to have evolved, so they have to be alien nanotech???
Obviously some weird kind of conspiracy theory cross technobabble – but very seductive, to the uninformed. Some of the comments are also just out of this world – literally!
Fortunately, there are some real science videos out there too – some of which I have also used in lecturing, if only to illustrate just how cool structural biology can be when used to study viruses. Prime among these is one of T4 virus (Enterobacteria phage T4) infecting E coli; another magical one from the same source is a depiction of the molecular motor which winds DNA into T4 heads. A longer video has Michael Rossman, whose lab did the structural work behind the videos, explaining how the phenomenon could be useful in understanding viruses like herpesviruses in humans, which also appear to have molecular motors for DNA delivery – and, of course, how we can mess with them.
Self-assembly of viruses is also a good topic for video – and the full-length Seyet T4 video is stunning in this regard. So too is this one, showing a PhiX174 microvirus particle assembling. One of my favourites, though, is the simplest: this is the depiction of how simple shapes can be induced to self-assemble into a virus-like particle - just by shaking.
I suppose, like everything, you get what you pay for with YouTube: which is nothing, most of the time.
But every now and then, a gem – which is what makes it fun to look. I’m off to hunt down
a Rolling Stones video virus replication videos!