specific prefrences about the key conformation bonds are c4'-c5 ' ( psi = 60 degrees ) , c5'-o5 ' ( phi = 180 degrees ) , o5'-p ( omega = 110 degrees ) , p-o3 ' ( omega ' = 310 degrees ) , o3'-c3 ' ( phi ' = 210 degrees ) , c1'-n ( chi = 20 degrees ) , c2'-o2 ' ( theta = 300 degrees ) for nucleotidyl units with c3 ' -endo ribose pucker .
C0030106
o3
C0030054
o2