Figure 10.

Do shared DNA-backbone contacts mediate cooperative interaction? This view of our current model of the cooperative assembly ((24); see also Figure 1) emphasizes a portion of the AGT–DNA interface. Two protein nearest-neighbors (colored blue and light green) and a segment of the shared DNA surface are shown, as well as a small segment of a third protomer (green). DNA atoms are colored according to the CPK convention (oxygen, red; phosphorus, orange-yellow; nitrogen, light blue; carbon, gray). The residue numbers of amino acid side chains that share DNA contacts are indicated.