MAGIC NUMBERS IN PROTEIN STRUCTURES

A homology measure for protein fold classes has been constructed by lo cally projecting consecutive secondary structures onto a lattice. Taki ng into account hydrophobic forces we have found a mechanism for forma tion of domains containing magic numbers of secondary structures and m ultipla of these domains. We have performed a statistical analysis of available protein structures and found agreement with the predicted pr eferred abundances. Furthermore, a connection between sequence informa tion and fold classes is established in terms of hinge forces between the structural elements.