Table 1.

Types of cryptic sites in the CryptoSite set of 93 proteins

Type*	Origin of the site being cryptic	No.†
LC	Loops protruding into the site, making it closed to ligand binding	21
LO	Loops too open in the unbound structure, making the pocket not well-formed	18
S	Side chains protruding into the site in the unbound structure	18
LM	Loops missing in the unbound structure, leading to loss of the pocket	11
I	Interdomain cryptic site, affected by hinge or other motion of the two domains	11
U	Unstructured regions in the unbound structure, in most cases N or C termini	3
SC	Secondary structure elements too close, closing on the pocket	5
SO	Secondary structure elements too far, making the pocket too open	2
SM	Secondary structure elements missing in the unbound or bound structure	2
CT	Very large conformational transition (calmodulin)	1
F	FTMap fails: Pocket is too weak to bind probes	1

^*Notation used in SI Appendix, Table S1.

^†Number of cryptic sites of the particular type among the 93 proteins.