entities:
  # Specify a designed protein chain
  # random number between 120 and 140 of designed residues (inclusive)
  - protein:
      id: A
      sequence: 120..140
  # Specify a non-designed protein chain
  # fixed 20-mer, all residues fixed
  - protein:
      id: B
      sequence: GGGILPWKWPWWPWRRGGG