{HEAD ~ Box B} lies {TAIL ~ 21 amino acids C terminal} to Box A from amino acids 43 139 
lies
{ HEAD ~ Box B } lies { TAIL ~ 21 amino acids C terminal } to Box A from amino acids 43 139
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH