The WLoop Homology Modeling Server is a tool to predict protein loop backbone structures from their sequences and their flank backbone structures.

Atomic coordinates of the alpha carbons of the regular secondary structures flanking the loop must be provided. It functions upon a knowledge based principle. Presently WLoop can accept attempting to build loops of size three to twelve.

To use this service, you must provide:
  A PDB formatted file with the missing parts to fulfill.
  The sequence of the complete protein.
  The secondary structure of the protein