{HEAD ~ A GC nucleotide repeat region encodes} alternating prolines and {TAIL ~ alanines} from amino acids 467 480 
alternating
{ HEAD ~ A GC nucleotide repeat region encodes } alternating prolines and { TAIL ~ alanines } from amino acids 467 480
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH