Reading the genome

Scientists at the US Lawrence Berkeley National Laboratory have made a major step forward in understanding how the information in our DNA is "read" - a process known as transcription - publishing their results in the journal Nature.

Eva Nogales and her team used a technique called cryo-electron microscopy to zoom in on the molecular machinery responsible for transcription, taking snapshots of its structure at an incredibly detailed level. This machinery, known as the "transcription pre-initiation complex", contains a number of different proteins which help to load RNA polymerase II - the enzyme responsible for "reading" genes - onto DNA so it can start working. In these experiments, the scientists produced some of the components of the complex in a test-tube so they could study them relatively easily.

The snapshots taken by the team help to reveal how RNA polymerase II is attracted to DNA and kept there, as well as how it chooses the exact place to start reading a gene. Next, the researchers plan to work towards spying on the whole transcriptional machinery - a huge structure in molecular terms. And although it's technically challenging, this kind of research is helping us to understand how our genes work on the deepest level.