A protein structural motif that bends DNA



The prokaryotic protein HU, integration host factor (IHF) from Escherichia coli and transcription factor 1 (TF1) from bacteriophage SPO1 are closely related molecules. Biochemical results suggest that the role of these proteins is to bind and bend DNA. From the high-resolution structure of HU, we propose a model for thisinteraction with DNA. Crucial amino acid differences between the proteins can be rationalized in terms of their different specific functions.