Then the question about the other 1,000 bases, how do they get covered, they probably get covered by A protein. But then there was a lot of work about discussion about direction, I think you did some experiments with Joe Butler on this didn't you, to find the direction of assembly on the RNA; I've forgotten how you did that.

[Q] We could recognise the ends, I think.

Oh, the ends of it, yes, there's a slight difference in the ends, the tilt of the protein. So... so that system... so it means it's really... it has a biological role, so... so it was some biology entered into a specific recognition, which is what's required. So this is corrected... so it wasn't just a protein cell schlurping in some RNA. So I was very pleased with that and it still remains the best worked out system in viral assembly, as far as I know; where they have been worked out in detail. It was a simple system, the helix is simple to work with as is seen from the spherical virus, this was the... the very best system. So those papers were published in 1971 and I don't know of any other case, although I've stopped looking, I must say now, where this was worked out. And to this day I don't think it's clear how this spherical virus... its recognition probably is part of the RNA. I can imagine it's the same thing, part of the RNA will be some kind of loop structure which is recognised by some partial aggregate, a ring of six or a ring of five sub units of the icosohedral lattice. I thought at one time we would... work on that but one had... by that time we were moving onto other subjects, so...

[Q] The crystals, the fact that we had crystals and the X-ray work progressed on those.

Yes... of course... oh yes... but, now with the crystal, the disc... the disc had a molecular weight of 600,000.

[Q] Yes.

It was the largest object ever, at the time, to be crystallised and solved. It was the first... and to do that; it was a heroic effort, Ann Bloomer, using Uli Arndt's X-ray data collection system that is using a rotating, what was it called?

[Q] Rotation camera.

Rotation camera, and it was solved in 1978 to high resolution. So 76 to five angstroms and to 78 in... low... high resolution.

[Q] Yeah... Yes.

The disc, so that was... but... that... but, you see, being a low resolution, it explained how the hairpin entered the... so the idea was that the hairpin entered through the hole down the middle, a hole in the middle. This loop was recognised by the jaws, there would be two layers with the disc structure. And helix entered, RNA helix and then some other, the dislocator, I can't do that. And the loop was recognised, the guanine's in the loop were recognised.

[Q] Could you see the advantage why it's so far along?

No, we can't, I can't see the advantage. It must be... people have found the origin certainly of some other helical viruses and they are all some distance away. But this... this was met with a lot of suspicion until the Strasbourg people, that is... no, of course, other of the virus plant, virus labs jumped into the act. And a man called Leon Hirth published a paper to prove that this was the case. And... and it was originally he... they published... referred to our work, and... but they showed that they were doing the assembly into a partial intermediates in the assembly. You could see two, two RNA tails coming out of the partially assembled rod; which was the proof that we had the hairpin structure going in.

[Q] Yeah.

It's quite interesting. I think they were quite peeved that we did this because they were professional virologists. And so a bit interesting on the ethos of science... and in the first days they referred to our papers and gradually they published more papers. Our papers got pushed in and so the assembly mechanism is due to Hirth et al. at least in Strasbourg. But we showed it was very clear from your work, in fact you were labelling the ends, it was rather more cumbersome than it just seemed, the two tails, because we had to spread out the RNA to see the two tails, so it was quite pleasing; but, it was the... solving a problem like that. I... one could have gone on had I been a so to speak, a biophysicist, I would have gone onto spherical viruses and done some assembly things and looked at the intermediate aggregates. But one had to give it up to do something new.