PREAMBLE
Before leaping into the new theory let’s a have a look material which is new to the author since Feb 2022. The work of Wu, Biegeleisen, and Xu was something the author had been only vaguely aware of until encouraged by Sean Kettle.
It is fair to say that apart from the anxiety of having to plough through technical material at the edge of one’s competence there was also considerable anxiety about this work by very well qualified, technically adept scientists. Having held on to the ASDT for 40 years the author was worried that his baby would turn out to be ugly. W-C establishment – I felt your pain:).
But Samir’s authoritative interest and Sean’s kindness gave the author the confidence to make it possible to take the trip. And what a journey it has been.
HOOGSTEEN/CURTIS: the implications
Karst Hoogsteen identified alternative base pairing orientations in his 1959 paper and in 1963 produced a paper which more emphatically stated the case for the better fit of his pairing orientations over the W-C layout. His model makes the pairings tighter with shorter bond lengths and it makes them much more even in length/diameter across both types of base pair.
From 1995 Mark Curtis started examining the W-C base pairings ‘…more as an artist than as a scientist.‘ focussing on the logic of the geometry and independently came up with pairings similar to Hoogsteen’s.
However what is really striking about the Hoogsteen/Curtis (H-C) departure is that each pair is connected by 2 hydrogen bonds whereas the W-C has Adenine-Thymine with 2 hydrogen bonds but Cytosine – Guanine connected by 3 hydrogen bonds. The author found that answering an unasked nagging high school question as to why the C-G base pairing apparently is so much more strongly bound with 3 hydrogen bonds than the T–A with only 2 hydrogen bonds. This alone makes the H-C appear to be very deserving of careful reassessment.
The significance for the ASDT is that both the symmetry and the even strengths of the hydrogen bonding make the sinuous wave motion far more viable. The H-C is just a much neater package.
The other thing that struck the author was Curtis’s suggestion that the H-C opens the possibility that the bases could now be attached to the sugar phosphate chains by hydrogen bonds rather than the covalent glycosidic bond which the W-C, SBS and most others assume.
The potential significance of all of this may be that it would make the molecule both more flexible and more symmetrical and this would play into the idea of the dynamism that is central to the ASDT. It also may help explain the ease with which the molecule is capable of also forming the intercalated 4 strand structures of Wu and Biegeleisen. This is another interesting speculation and should be examined by the open minded researchers we are all hoping to find.
MOVING FORWARD: ASDT IN CONTEXT
The author has only recently seen and understood the Wu and Biegeleisen(WuB) models, the H-C work and the others. The ASDT offers a credible bio evolutionary pathway by way of the inherent sequence specific functionality in terms of template formation for mRNA coding and protein synthesis. This would see the ASDT as the ancestral DNA entity.
If the ASDT model is taken seriously by researchers, scenarios can be developed to establish likely transitions from the ancient ribonucleoprotein world (RNP) to the DNA dominated era in which we exist. For instance what simple coded molecule or type of molecule could this new dynamic/functional DNA have delivered to the RNP entity housing it that gave it such a massive advantage?
From that point on ASDT DNA would have taken over across the board delivering 50 times faster protein synthesis. It would have been like a spark of life to the existing RNP world.
With this massive shift in speed and energy things would have moved swiftly and probably quite chaotically and there would have been a transition to attain more stability, to calm things down. One way to go would have been to make the DNA circular, the route taken by bacteria, the prokaryotes and the other would have been the way eucaryotes went by integrating proteins like histones.
From there you would be able to chart a co-development of ASDT and the histones etc to the extremely intricate and compressed intercalated structures like Wu’s and complexes like the protamine-DNA described by Bergeleisen. These require significant changes in basic structure to accommodate the intercalation and all the while preserving the integrity of the sequences. It’s hard to overstate how amazing this molecule really is or might be. It is really quite astonishing.
With this as a working evolutionary premise examined by researchers with properly open minds really solid work could be done. It is literally impossible to envisage how much important scientific work has been left unexplored and not discovered because of the central failure of the W-C committed DNA establishment to do their jobs properly.
FINAL PLUG
The inert rigidity of the W-C stands in stark opposition to the vibrantly functional ASDT and is an analogy for the relationship between the W-C establishment and the proposers of the alternatives -Hoogsteen, Sasi, Wu, Xu, Delmonte, Bergeleisen, Curtis etc. This analogy is the major theme of both the short story ‘Being Misunderstood’ and the novel ‘A Singing Dancing Thing’.