Table 2. Examples of protein families with the disorder-to-order transitions on or near interfaces.

Family name, interacting partner, CBM	PDB code	p-value	DO on inferred interface, %	Function of disordered region
Trypsin-like serine protease, BPTI/Kunitz family of serine protease inhibitors smart00020, cd00109, CBM#112, 99	1P2M, 1CHG	1E-8	30.0	Residues which surround active site in chymotripsinogen (monomeric state) become fixed upon activation (in the complex with chymotripsin).
Ephrin receptor ligand binding domain, Ephrin pfam01404, pfam00812, CBM#8, 9	1KGY, 1NUK	1.5E-07	6.8	Unbound ephrin receptor contains partially disordered loops. In the complex (bound to ephrin), these loops are ordered to form the ligand-binding channel.
Malate synthase G cd00728, cd00728, CBM#23	2GQ3, 1N8I	2.5E-09	23.8	One disordered loop region in a monomer forms intermolecular beta sheet with corresponding residues (ordered) on other monomer. The loop ordering suggests an allosteric interaction between the loop and the co-enzyme A binding pocket.
Ubiquitin carboxyl-terminal hydrolase, family 1, Ubiquitin pfam01088, cd01803, CBM#5	1XD3, 1UCH	2.5E-08	30.2	A disordered 20-residue loop is positioned over the active cleft and becomes ordered upon complex formation. It prevents binding the larger substrates and plays role in defining substrate specificity.
Beta-carbonic anhydrase clade C cd03378, cd03378, CBM#47	2A5V, 1YM3	1.3E-06	5.6	Local disorder in a monomer allows active site to be open. In tetramer, the disorder region forms an (ordered) alpha-helix that packs on the other monomer of the essential dimer to create a cavity and restrict access to the active site.
Dihydroneopterin aldolase and 7,8-dihydroneopterin triphosphate epimerase cd00534, cd00534, CBM#497	1NBU, 1Z9W	0.0416	7.7	Enzyme contains a flexible, disordered loop with the catalytic residue Glu22 that hinders active site formation. In allosteric regulation, substrate binding drives conformational changes including ordering of this loop to convert from inactive to active form.
Copropor-phyrinogen III oxidase PRK05330 PRK05330, CBM#8	1TKL, 1TK1	0.0004	30.0	Monomer in an open form has disordered residues on interface which get ordered upon dimer formation.

Columns list names of protein families together with the name of interacting partner, CBM identifier, PDB codes of structural representatives of a complex and a monomer, binomial p-value, percent of disordered residues on a monomer (monomer assignments were taken from ASU and in all but one case were confirmed by PISA) corresponding to the interface region of a complex and description of function of disordered region (references are given in SM). Fraction disorder on interface is averaged over different conserved binding modes of a given family. For references, see Table S1(b).