MIT researchers found the expression of a gene can stimulate or suppress the activation of neighboring genes, by altering the biophysical properties of the DNA strand. The new findings could make it easier to control the output of synthetic gene circuits.

The enzyme RNA polymerase reads a DNA template to build RNA one nucleotide at a time, but how it performs its core chemistry is unresolved. New cryo-EM structures capture the enzyme in intermediate states, showing for the first time that RNA polymerase catalyzes reactions through the precise alignment of substrates and using a coordinated chain of water molecules that act as a proton shuttle. Because this mechanism is conserved across all life, the findings provide a universal blueprint for gene expression and explain how certain mutations disrupt transcription.