echo "The next alpha-beta structure is known as the beta horseshoe."
echo "This protein is porcine ribonuclease inhibitor and its"
echo "cellular function is to limit RNase activity in the cell."
load 1DFJ.pdb
wireframe off
select 1-457I
color blue
cartoon
rotate x 114
rotate y 43
rotate z 22
pause
echo "Note the repeating strand-helix-strand structure in the"
echo "beta horseshoe."
echo
echo "This molecule is significantly larger than the enzyme it"
echo "inhibits (the inhibitor is 457 residues, RNase A is 124)."
echo "Drawing RNase A completes the model."
select 1-124E
color red
cartoon
echo "Note that RNase A is associates tightly with just one area"
echo "of the inhibitor. The contact surface includes the active"
echo "site of RNase A."
pause
zap