Lac repressor: Difference between revisions

Upon recognizing the specific operator sequence, the non-specific binding converts to <scene name='Lac_repressor/1l1m_ca_specific_bindiing/3'>specific binding</scene> (derived<ref name='alphac' /> from [[1l1m]], 20 [[NMR Ensembles of Models|NMR models]]). During this conversion, the hinge region changes from disordered loops to {{Template:ColorKey_Helix}} (<scene name='32/324680/4/2'>highlight new helices</scene><scene name='Lac_repressor/1l1m_ca_specific_bindiing/4'>.</scene>), which bind to the minor groove of the DNA. As explained below, this binding stabilizes a '''kinked ("bent")''' <font color='#ae00ff'><b>DNA double helix</b></font> conformation. What percentage of time this DNA sequence spends in  a kinked state, in the absence of bound lac repressor protein, is not known, but it may be a significant percentage (see next section below). <scene name='Lac_repressor/1l1m_ca_specific_bindiing/6'>Animating</scene> these 20 NMR models can be compared with the animation of the non-specific binding.  See [[Lac repressor morph methods]]. {{Template:Button Toggle Animation}}