load =1r4o

define A_maj ((A.N6 or A.N7 or A.C5 or A.C6 or A.C8) and dna )
define A_min ((A.N3 or A.C2 or A.C4) and dna)

define T_maj ((T.O4 or T.C4 or T.C5 or T.C6 or T.C7) and dna)
define T_min ((T.O2 or T.C2) and dna)

define G_maj ((G.O6 or G.N7 or G.C5 or G.C6 or G.C8) and dna)
define G_min ((G.N2 or G.N3 or G.C2 or G.C4) and dna)

define C_maj ((C.N4 or C.C4 or C.C5 or C.C6) and dna)
define C_min ((C.O2 or C.C2) and dna)

define major_groove A_maj or T_maj or G_maj or C_maj
define minor_groove A_min or T_min or G_min or C_min

define p_PO4 *.OP? and dna
define np_PO4 *.P and dna

define p_sugar *.O?' and dna
define np_sugar *.C?' and dna

define p_base ((*.O? or *.N?) and dna)
define np_base (*.C? and dna)

define p_dna (p_PO4 or p_sugar or p_base)
define np_dna (np_PO4 or np_sugar or np_base)

define p_maj (major_groove and p_dna)
define np_maj (major_groove and np_dna)

define p_min (minor_groove and p_dna)
define np_min (minor_groove and np_dna)

define p_protein ((oxygen or nitrogen) and protein)
define np_protein ((carbon or phosphorus or sulfur) and protein)