Protein Structure Superposition by Curve Moment Invariants and Iterative Closest Point

Superimpose one protein tertiary structure to another can help to find similarity between them and further identify functional and evolutionary relationships. We first extract invariant features under rigid body transformation for each protein backbone which is represented by alpha-carbons of all the residues. Then, the invariant features are embedded with Iterative Closest Point algorithm for superposition. With several initialized orientations, pairwise alignment can be achieved accurately only by few iterations. Experiments indicate that our proposed algorithm is competitive with several well-known algorithms and with smallest root mean squared distance.