subroutine char MY_KEY
show vari MY_KEY
echo " -------------- NEW LINE ------------"
wr sele MY_KEY end coor pdb
set vari IATOM inte atom sele MY_KEY end
show vari IATOM 
if ( IATOM .le. 0 ) return
set vari IATOM2 inte atom sele by bond atom numb IATOM end
show vari IATOM2
wr sele atom numb IATOM IATOM2 end coor pdb

echo JOIN RESIDUE IATOM IATOM2

join resi IATOM2 IATOM
!rena seq Z sele by resi atom numb IATOM end append
!rena resi CTR sele by resi atom numb IATOM end 
wr sele by resi atom numb IATOM end coor pdb

key MY_KEY sele MY_KEY .a .n atom numb IATOM end
rewind file
return