The role of direct readout

The large deformation of the DNA helix involves the insertion of two pairs of phenylalanine rings (F39, F56, F130 and F147), into bps 1 and 7 in the TATA element. This interaction results in -45° kinks, coupled to untwisting and vertical separation of the bp. 

ATH2 ( 19) 1 SGIVPTLQNI VSTVNLDCKL DLKAIALQAR NAEYNPKRFA AVIMRIREPK 

The energy calculations showed that phenylalanine residues involved in the DNA kinking cannot discriminate A T from T A, or from C G, for that matter 

The energy cost of DNA bending an alternative sequence-dependence mechanism. 

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