+---COMP:ADJ-N(for)---+----COMP:N-N(of)---+     
     +MOD_ATT+MOD_PRED:N-+            +MOD_ATT:+           +MOD_ATT+     
     |       |           |            |        |           |       |     
 __NODE__ protein is necessary for maximal activity of __NODE__ protein .
MOD_ATT:N-ADJ (protein,__NODE__)
MOD_PRED:N-ADJ (protein,necessary)
COMP:ADJ-N(for) (necessary,activity)
MOD_ATT:N-ADJ (activity,maximal)
COMP:N-N(of) (activity,protein)
MOD_ATT:N-ADJ (protein,__NODE__)