Figure 4. Structure of GR DBD and its interaction with DNA GRE. A: Zinc finger structures in DBD of hGR. Numbered eight cysteine (C) residues chelate Zn2+ to form two separate finger structures. Red-colored amino acid residues form -helical structures. Box with bold line indicates lever arm, while that with dashed line shows D-box. Modified from (30). B: 3-Dimensional model of the physical interaction between the GR DBD and DNA GRE. The N-terminal’s first -helix of the GR DBD lies in the major groove of the double-stranded DNA, while the C-terminal part of the second -helix is positioned over the minor groove. The image was created and donated by Dr. D.E. Hurt (National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD). Box with bold line indicates lever arm, while that with dashed line shows D-box. Modified from (30).