3D Model of DNA Double Helix from X-ray Diffraction Data

'Did Watson and Crick really steal Rosalind Franklin’s data' - this age-old controversy has takers on both sides. The latest by this Guardian article by the famous British Zoologist and science communicator Matthew Cobb. The article refutes the claim that Watson and Crick stole Rosalind Franklin’s data, arguing that while they used her X-ray crystallography images, they did so without consulting her or obtaining permission, which was an ethical lapse but not outright theft. Franklin’s contributions were crucial to understanding DNA’s structure, and her data were vital for Watson and Crick’s model. The article acknowledges that Franklin deserved recognition, and if she had lived, she likely would have shared the Nobel Prize for her contributions.

Those who read James Watson's memoir  - 'The Double Helix', know that Rosalind Franklin is portrayed in a somewhat critical light, especially in relation to her role in deciphering the structure of DNA. In this book, although Watson acknowledged Franklin's X-ray crystallography work, but presents Franklin as a rather difficult and temperamental colleague, often focusing on her perceived "cold" demeanor and stern personality. In the Guardian article, Cobb argued that Watson’s portrayal of events in 'The Double Helix' minimized Franklin’s role, shaping the myth of data theft.

Fast forward to the modern era, let’s put ourselves in the shoes of Watson and Crick—but with a twist. What if we could use Rosalind Franklin’s X-ray crystallography data and add extra parameters when necessary to build a 3D model of DNA from scratch? Unlike their iconic physical double helix model, we’ll create a virtual 3D representation (though, with access to a 3D printer, the physical model is just a step away!). Keeping the controversy aside, this is a mere exploration of what it takes to piece together the DNA structure, armed with computational tools and insights into the double helix. Below, I’ve prepared a code that generates a 3D model of DNA using two complementary strands as inputs. The code incorporates essential parameters from the Watson and Crick model, progressively adding only the minimally required features. I’ve also highlighted the parameters that can be derived from X-ray crystallography data and those that require beyond crystallographic evidence to complete the model. Experiment with the sequences using the UI provided and see the double helix come to life!

(Rendering the 3D structure may take some time. Thank you for your patience.)