1) Download 1HT0 from www.rcsb.org

2) Shift + Left click on “show” and “side” columns

3) Shift + Left click on “ribn” column

4) Color à By Secondary Structure

5) Color à By Chain

Questions:

A) What secondary structure forms the dimmer interface?

B) Take a screenshot of the dimmer in ribbon mode.

C) Show the ligand (NAD) as ball+stick while the protein is in ribbons. Take a screenshot.

D) Show the coordination of both Zn atoms in one chain (one is near the NAD, the other isn’t).

            Do not use ribbon mode, show the side chains.

            Only show residues within 4 Angstroms of the Zn atom.

            Use the Display and Build menus to show H-bonds that coordinate the Zn that is coordinated by four Cysteine residues.

            Take a screenshot.

E) Mutate Cys174 to a lysine. Why would this be a bad mutation (Hint: cycle through the rotamers (alternate conformations)) ?

            Take a screenshot.