Given two or more superimposed structures, Match→Align creates a corresponding sequence alignment. The user specifies a distance cutoff for residues allowed to be in the same column of the output alignment. In proteins, the distances are measured between α-carbons. The method is independent of residue types and how the structures were superimposed.
The figure shows a superposition from MatchMaker of five proteins from the SCOP WD40 superfamily and a corresponding sequence alignment from Match→Align, automatically shown in Multalign Viewer. In the sequence alignment, light green and yellow boxes indicate strands and helices, while the headers RMSD and Conservation show spatial and sequence conservation, respectively.

Potassium channel (Protein Data Bank entry 1bl8) on a dark slate blue background with potassium ions shown in firebrick. The channel is comprised of four chains. Each chain has been rainbow-colored from blue at the N-terminus to red at the C-terminus, but only the surface of the channel is shown. The surface has been sliced with a per-model clipping plane. The surface cap color is plum except with opacity set to 0.8. The shininess and brightness have been set to 128 and 8, respectively, and the lights on the scene have been moved from their default positions. The subdivision quality (related to the smoothness of the spherical ions) is 5.0, and the molecular surface was computed with probe radius and vertex density set to 1.0 and 6.0, respectively. (More samples...)