Snapshots from the copy chemistry
The newly crowned Nobel Prize winner for chemistry is called Roger Kornberg. He is honored for his many years of research on "the molecular basis of eukaryotic transcription". The contribution of the American has made one of the most important processes in the cells of higher organisms easier to understand.
If the official justification of the Stockholm Nobel Prize Committee for their decision cannot do without the words "life", "cells" and "genome", then one would think that the annual prize for medicine has once again been awarded. And that would be wrong. Medicine is also biology, and this is inconceivable without chemistry – and advances in one field often stimulate great discoveries in the related field. The current laureate Roger Kornberg from Stanford University will not go down in history as the winner of the 2006 Nobel Prize in Chemistry for no good reason – even though his passion for research has focused on a central topic in biology for more than three decades: transcription. With their help, living beings translate genetic information into tangible commands and tools.
The research elite has known how transcription works for almost 50 years and high school students have been learning it for at least 30 years. As early as 1965, three researchers received a Nobel Prize (at that time really the one for medicine) after they had clearly deciphered and explained the underlying control mechanisms.
A brief outline of the processes, i.e. the translation of genes on the DNA into a transport form called messenger RNA: Take a suitable piece of the DNA to be translated, add building material for RNA (in the form of nucleotides, i.e. base-carrying sugar building blocks), add the central tool for reading DNA and building the RNA chain (a protein called polymerase) - eh voilá, you're good to go, even in the test tube.
At least in bacteria and in principle - and if a few fine ingredients are also mixed in, such as the activating so-called sigma subunit, and a point at which the polymerase tool sees a meaningful starting point for its work (the promoter). As early as the 1970s, ensuring these small details was not a problem, and research into ever finer details of bacterial transcription was progressing rapidly.
Prize winner Roger Kornberg was already working on the differences in the genetic material of bacteria and higher organisms with a real cell nucleus, the eukaryotes, at the same time. His working group now began the task of allowing the transcription process familiar to bacteria to take place in their eukaryotic laboratory model organism, baker's yeast. Perhaps the researchers initially hoped to just sit back and watch how the large organisms organize messenger RNA construction compared to the small bacteria, and then quickly publish the whole thing. If that had worked as planned, it would hardly have won a Nobel Prize.
It's a good thing for Kornberg that the experiment didn't make any headway from the start. Something was obviously fundamentally different in the mRNA construction of eukaryotes. Over the years, a long list of differences has accumulated: for example, the DNA of the higher organisms is well packaged and rolled up on protein spindles – one of Kornberg's first works de alt with their shape – which first have to be complimented to the side by a special signal. According to this, not only one polymerase is responsible for RNA construction, as is the case with bacteria, but three different ones, each with a special function. The starting points for reading eukaryotic DNA also look very different, and DNA sections located far away from the site of the event, the enhancers, have to be co-activated in order to start transcription. Actually, a number of different transcription factors are necessary to get things going.
If you throw it all together – and in addition to RNA building blocks, DNA, transcription factors, enhancer activators and the responsible RNA polymerase II, "everything" also includes many other proteins, which are a crucial protein discovered by Kornberg Form a universal tool called the "mediator complex" - then at first glance, all you can see under the microscope is a large, confusing lump of biomass that sucks in DNA on one side and spits out messenger RNA on the other, more or less stuttering, if all goes well. To put it mildly, it is a bit confusing to say which of the fiddly ingredients is doing what.
Roger Kornberg - and a large number of fellow campaigners and suppliers - nevertheless managed to break down the events in detail. To do this, they not only developed their yeast transcription model ready for series production, but also many new techniques and tricks of crystallography and X-ray structure analysis. Kornberg's innovative contributions from twenty years of work, in which he combined electron microscopy and X-ray crystallography, for example, finally made it possible to take a really close look at the cell machine and draw conclusions about the actual molecular processes from 2001 onwards.
Teams from Kornberg's orbit created usable snapshots of the working transcription complex for the first time with a resolution of less than 0.3 nanometers [1, 2]. Little by little, a well-founded theory of the function and distribution of tasks of the polymerase and all of the transcription participants grouped around it emerged from many frozen individual images before, during and after the reading, the collection, connection and spitting out of the individual building blocks, the sliding of the complex along the DNA, the separation process of paired DNA and RNA and the start and stop signals involved.
All of this provided a tremendous number of exciting starting points for future tasks: errors in the transcription apparatus often lead directly to diseases such as cancer, heart problems, metabolic disorders or immune system defects in humans, who are probably the most interesting eukaryotes for us all; but research into the maturation of stem cells and a number of other current medical issues also benefit from precise knowledge of the central cell program of transcription.
All of this certainly justifies the Stockholm Committee's decision to declare Kornberg's field and his advances worthy of an award. The reason why it affects him alone - when many other researchers have brought countless details into the overall picture - is probably because none of them or only one could be honored as an example. With the Stanford University researcher, at least no one got the wrong one. Whether his speci alty is medicine or chemistry shouldn't matter to him or any of his colleagues. In any case, some would not only say that biology is also chemistry, but that all natural sciences are ultimately only mathematics. If one were really consistent there, then there would unfortunately be no Nobel Prizes for Kornberg, like for all mathematicians.