Freeze is a tool that prevents a segment of a protein from moving during rebuilding and pulling. Freeze can be applied at four different scales: the entire protein may be locked (hotkey: L); an individual structure may be frozen (right-click and select from pie menu); a single amino acid may be frozen (shift-click); and even a single sidechain can be frozen (shift-click). When a structure is frozen it changes into a light blue color and is translucent. This tool is used to isolate parts of proteins for use with other tools.
Freezing and the Pull Tool Edit
When using the pull tool frozen areas of proteins will not move. When freeze is used globally the pull tool does nothing because there is nothing that is unfrozen to pull. The pull tool can be used to move discrete parts of a protein separated from one another by freezing; only sections that are connected to the place you click and drag from that are not separated by a frozen section will be affected.
Freezing and the Wiggle Tool Edit
The wiggle tool when applied globally moves frozen sections without there being any difference from when the sections are not frozen. However when local wiggle is used it will affect the structure selected and wiggle all of the amino acids up to end at the point where the structure changes or where an amino acid is frozen. This means that by freezing at any given point on a structure players may isolate the area which is wiggled to between a freeze and the end of a structure or between two frozen segments. When isolating sections of a protein for use with local wiggle, players most often change the entire protein to have only loop structures. The most notable use for this isolation is local wiggle strategy.
Freezing and the Rebuild Tool Edit
Freezing can be used with the rebuild tool in a way similar to that described in the section above. The rebuild tool will affect a section until there is a change in structure or until there is a frozen segment. Players use freezing on single amino acids to choose a specific section to rebuild.
Freezing and the Shake Sidechains Tool Edit
Shake sidechains will not change the position of any frozen sidechains.