The P5 position refers to {TAIL ~ the amino acid residue} that follows the amino acid residue that occupies {HEAD ~ the P4 pocket} 
The P5 position refers to { TAIL ~ the amino acid residue } that follows the amino acid residue that occupies { HEAD ~ the P4 pocket }
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD