load ==1MHD.pdb
background [251, 248, 243]
color [130,116,107]
restrict DNA 
wireframe 50
cartoons off
define set1 *.o?*
define set2 *.OP?
define set3 *.N? and dna

select set1
cpk 150 
color cpk

pause

select set2
cpk 150
color green

pause

select set3
cpk 150
color blue