As it is, the functions of FREEZE and LOCK (used interchangably in the current version) are confusing. FREEZE, intuitively, should fix the relationship of an amino acid with its neighbors, AND, fix its place in space. Sometimes this happens. Sometimes it acts like a damper allowing both relationships with neighbors to change and moving in space. Sometimes one or both functions do not work at all.

I would like to see FREEZE divided into two functions: freeze the relationship of an amino acid with its local neighbors, AND, freeze the amino acid in space. The user should be able to do both or each function separately. I would suggest using two words to equal two functions: FREEZE = fixed in space. LOCK = fixes relationship with neighbors.

In this way a section could be LOCKED and moved around as a block. Presently, moving blocks of amino acids are difficult, if not impossible, without major disruption to the rest of the protein.