Fig. 1: Top view of the ScNsrR/hmpA1 operator complex.
NsrR subunits Cα tracings are depicted in blue and gold with ribbons indicating α-helices and arrows β-strands. DNA strands carry nucleotide numbers and are shown as cyan and burgundy ribbons, with stars marking four BII backbone conformations in the central region. Cluster atoms and histidine side chains forming hydrogen bonds to phosphate groups are depicted as spheres (Fe: red-brown, S: yellow, N: blue and C: gray). The first three helices and the labeled wing loop of each protein subunit interact with the DNA. Minimal and maximal P-to-P distances between phosphate groups across the minor groove are indicated with dotted lines and given in Å. The green dashed line follows the bp origins of the DNA double helix as determined with the program DSSR37.
