The Bristol DNA double helix
The elucidation of the double helical
structure of DNA by James Watson and
Francis Crick in 1953 was one of the key
findings of the twentieth century, paving
the way for virtually all modern
biochemistry. In the early 1950s there
were various theories about the structure
of DNA, including triple helices and
inside-out versions of the real thing but
none of these fitted the data in a way
that seemed plausible. Before computers
became powerful enough, the best way
to test structural theories was to build
physical representations using metal
models. Watson and Crick decided to tackle the DNA structure problem in this way and asked the
workshop in the Cavendish Laboratory in Cambridge where they worked to make those parts that
were not already available. They then used the available data, such as the relative proportions of
the individual components and data from Rosalind Franklin’s x-ray experiments, to build various
structures and the one that made both chemical and biological sense was the now-famous double
helix.
This iconic model is perhaps the best recognised representation of a biological molecule in the
history of science, and was immortalised alongside its creators in a famous photograph by Antony
Barrington-Brown. By a strange twist of fate this model subsequently spent many years housed
within Biochemistry at Bristol.
When the fledgling Department of Biochemistry was established at the University of Bristol, many of
its founding members of staff were recruited from Cambridge. This included, in 1968, Dr Herman
Watson (no relation to James!). Herman Watson was a protein crystallographer who had learned his
trade from the Nobel laureate Max Perutz at the newly established Laboratory of Molecular Biology
(LMB) in Cambridge. X-ray crystallography was a technique which had only recently been applied to
proteins, and both expertise and associated equipment were in short supply. When Herman Watson
moved to Bristol, understandably he was keen to bring whatever surplus equipment could possibly
be ‘spared’ by the LMB. This included several drawers of no longer used components for molecular
models. Included in this mix was Watson and Crick’s now dismantled and abandoned very first
model of the DNA double helix.
The model was reassembled and for many years it was discreetly displayed at one end of our
undergraduate teaching laboratory. At quiet moments during the long afternoons of practical
classes, many of our lecturing staff would proudly show off to our students this hand-built model
with its original scribblings on the tin-plate base pairs. These viewings were invariably accompanied
by an increasingly exaggerated story of the great heist by which Bristol had stealthily removed this
famous model from right under the noses of Cambridge colleagues.
But possession is only nine-tenths of the law. As the fundamental importance of Watson & Crick’s
seminal discovery became ever more evident, the Science Museum in London launched a hunt for
this iconic model. Quite how the trail eventually led to Bristol is unknown: it is assumed we were
betrayed by one of those quiet boasts to a practical class on a dark winter’s afternoon, inspiring an
unforgettable memory in a loose-lipped undergraduate. How the negotiations with the Science
Museum went is also a mystery; suffice to say they did manage to extract most of the original model
which is now on display in London and viewed by nearly 3 million visitors annually.
Nonetheless, Bristol somehow held on to two sets of the original tin-plate hand-cut base pairs and
these have been incorporated into our own (partial) replica of the very first model of the DNA
double helix. To celebrate our 50th anniversary, the model was completely renovated and provided
with a new display case in summer 2013. It still sits at the front of our first-year teaching laboratory,
and is repeatedly shown off to potential new students at open days. Its location in the teaching lab
means that this inspiring model can continue to provide our students with a beautiful and
unforgettable link to one of the greatest discoveries in biochemistry.