AT-hook

AT-hooks also include a variable number of positively charged lysine and arginine residues on either side of the core sequence.

[5] In 1997 structural studies using NMR determined that a DNA-bound AT-hook adopted a crescent or hook shape around the minor groove of a target DNA strand (pictured at right).

Van der Waals interactions of the AT-hook with the adenines play an important role for the specificity of the position.

[8] The figure shows the position of the main chain to allow hydrogen bonds with the minor groove thymine oxygen atoms.

[9] Alterations or abnormal expression of the HMG proteins have led to metabolic disorders, such as obesity, type 2 diabetes, and cancer.

The second AT-hook of HMGA1 (black ribbon) bound to the minor-groove of AT-rich DNA. The amino-acid side chains and nucleotides have been hidden.
The phosphate backbone of the DNA shown in orange is faded to focus on the central region of the AT-hook. Shown in magenta are the side chains Pro35, Arg36, Gly37, Arg38, and Pro39. Made with PyMol. PDB code: 3UXW.
There are multiple hydrogen bonds shown in yellow. The interactions occur between Arg38 and Pro39 (3.8 Å), Pro35 and Arg36 (2.5 Å), and Gly37 and Arg38 (2.4 Å). The red sphere represents a water that forms a hydrogen bond 2.7 Å from Arg38 with the bond shown in yellow. Made with PyMol. PDB code: 3UXW.