CHIME EXERCISE

 

1TRO: E. Coli Trp Repressor Protein Complex

In the Chime Exercise to the right, identify the following:

  • the Helix-Turn-Helix motifs and the two recognition helices in the major grooves

  • The 18 bp palindromic sequence that is recognized by these recognition helices.

  • the Trp molecules on the protein

  • Can you identify any direct contacts between the side chains and the bases in the major groove that might account for recognition specificity?

  • Identify some of the H-bonding contacts between the side chains and the non-esterified DNA backbone phosphate oxygens.