load 1DDN.pdb

define set1 *.O?* and dna
define set2 *.OP?
define set3 dna and (*.N?)

select all
wireframe off
cpk off
cartoons on
spin on

pause

restrict dna
zoom 90
cartoons off
color cpk
wireframe 80

pause

select all
color grey
color translucent 0.5
select set1
color cpk
cpk 150

pause 

select set2
color orange
cpk 150

pause 

select set3
color cpk
cpk 150