Some variants of the bacterial gene regulator CAP show marked differences in their affinity for DNA despite identical DNA-binding interfaces; NMR spectroscopy experiments now show that DNA binding is determined by the proteins’ internal dynamics over a broad range of timescales in a manner that cannot be predicted from the proteins’ ground-state structures.

Some variants of the bacterial gene regulator CAP show marked differences in their affinity for DNA despite identical DNA-binding interfaces; NMR spectroscopy experiments now show that DNA binding is determined by the proteins’ internal dynamics over a broad range of timescales in a manner that cannot be predicted from the proteins’ ground-state structures.