2BL
ATOM  C    CA   CB   CC   CD   CE   CF   CG1  CG2  CH1
ATOM  CH2  CI   CJ   O    OA   OB   OC   OD   S    N  
CONNECT -  C    CA  CB  CC  OA +
CONNECT  C    O
CONNECT  C    N  CB
CONNECT  CA   CD  CE
CONNECT  CC   OB
CONNECT  CF   CG1  CH1  CI  CH2  CG2  CF  S  OC
CONNECT  CI   CJ
CONNECT  OD   S  N