echo "Membrane proteins"
echo
echo "Our first example is alpha hemolysin. This molecule is a toxin produced"
echo "by Staphylococcus aureus that inserts into the red blood cell membrane"
echo "producing lysis of red blood cells."
echo "The protein is a heptameric protein. We will highlight each monomer in"
echo "turn."
echo
load 7AHL.pdb
wireframe off
rotate x 154
rotate y 50
rotate z -73
select 1-293A
color red
cartoon
pause
select 1-293B
color orange
cartoon
pause
select 1-293C
color yellow
cartoon
pause
select 1-293D
color green
cartoon
pause
select 1-293E
color blue
cartoon
pause
select 1-293F
color purple
cartoon
pause
select 1-293G
color white
cartoon
echo "Note the wrapping of beta strands in the lower 'trunk.' This is the section of"
echo "the protein that inserts into the membrane. The 'branches' are the"
echo "extracellular domain of the enzyme."
pause
echo "Rotate the molecule to see the channel or pore through the molecule"
pause
zap
echo 
echo "Another membrane protein is human aquaporin. This protein illustrates the"
echo "helical membrane spanning domain."
echo
load 1IH5.pdb
wireframe off
cartoon
pause
zap
echo 
echo "Another membrane protein is the E. coli chloride transporter."
echo
echo "Notice that there is no distinct pore in this molecule."
load 1OTS.pdb
wireframe off
select 1-465A
cartoon
select 1-465B
cartoon
pause
zap