LINUS perturbs three consecutive residues at a time to generate a new conformation. Five move types constitute the move set: α-helix, β-strand, β-turn, PII, and coil. Specifically, the five move types are:

1. α-helix: All three residues are assigned backbone torsion angles withihn a φ, ψ bin centered on φ = -64°, ψ = -43°.
2. β-strand: All three residues are assigned backbone torsion angles withihn a φ, ψ bin centered on φ = -135°, ψ = -145°.
3. β-turn: Either the first two residues or last two residues of the three residue segment are assigned to one of six β-turn conformations, and the remaining residue is assigned a conformation from the sterically allowed region of φ, ψ space (i.e. coil). The backbone torsion angles for the two positions in turn conformations are chosen from within the following φ, ψ bin combinations.

   Type I turn = choice{TO, TP }
   Type I' turn = choice{To, Tp; Tp,Tp }
   Type II turn = choice{TR, Tp; Tr,To }
   Type II' turn = choice{Tr, Tp; Tr, Tj }
   Type III turn = TP,TP
   Type III' turn = To, To
   

4. PII: All three residues are assigned backbone torsion angles withihn a φ, ψ bin centered on φ = -60°, ψ = 145°.
5. Coil: For non-glycine, non-proline residues each of the three residues is assigned backbone torsion angles with values from the allowed region of φ, ψ space chosen at random.

The allowed region of φ, ψ space for glycine is appropriately expanded and for proline it is limited to two regions centered on helical or extended chain conformation. Additionally, the coil move for proline samples cis-peptide conformations.

For each move, the peptide bond angle ω is set to 180° ± 5° and side chain chi angles angles (if any) are chosen at random from a list of sterically acceptable combinations. The ranges of acceptable torsion angles for residue rotamers are defined in chidict.py