Hierarchy of protein loop-lock structures: a new server for the   decomposition of a protein structure into a set of closed loops
  HoPLLS (Hierarchy of protein loop-lock structures) (http://leah.haifa.ac.il/~skogan/Apache/mydata1/main.html) is a web server that identifies closed loops - a structural basis for protein domain hierarchy. The server is based on the loop-and-lock theory for structural organisation of natural proteins. We describe this web server, the algorithms for the decomposition of a 3D protein into loops and the results of scientific investigations into a structural "alphabet" of loops and locks. 
Simon Kogan, Zakharia Frenkel, Oleg Kupervasser and Zeev Volkovich
physics.chem-ph cs.CE q-bio.QM