title: Interface property responsible for effective interactions of protean segments: Intrinsically disordered regions that undergo disorder-to-order transitions upon binding.
abstract: Proteins that lack a well-defined conformation under native conditions are referred to as intrinsically disordered proteins. When interacting with partner proteins, short regions in disordered proteins can undergo disorder-to-order transitions upon binding; these regions are called protean segments (ProSs). It has been indicated that interactions of ProSs are effective: the number of contacts per residue of ProS interface is large. To reveal the properties of ProS interface that are responsible for the interaction efficiency, we classified the interface into core, rim and support, and analyzed them based on the relative accessible surface area (rASA). Despite the effective interactions, the ProS interface is mainly composed of rim residues, rather than core. The ProS rim is more effective than the rim of heterodimers, because the average rASAs of ProS rim, which is significantly large in the monomeric state, provides a large area to be used for the interactions. The amino acid composition of ProSs correlated well with those of heterodimers in both the core and rim. Therefore, the composition cannot explain why the rASAs of the ProS rim are large in the monomeric state. The balance between a small core and a large rim, and the large solvent exposure of the rim in the monomeric state, are the key to the disorder-to-order transition and the effective interactions of ProSs.
authors.affiliation: Graduate School of Information Science, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Divya
authors.initials: D
authors.lastname: Shaji
authors.affiliation: Graduate School of Information Science, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Amemiya
authors.affiliation: Graduate School of Information Science, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Koike
authors.affiliation: Graduate School of Information Science, Nagoya University, Nagoya 464-8601, Japan. Electronic address: mota@is.nagoya-u.ac.jp.
authors.forename: Motonori
authors.initials: M
authors.lastname: Ota
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D030562:Databases, Protein; D064267:Intrinsically Disordered Proteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D060066:Protein Interaction Maps; D055503:Protein Multimerization
chemical_list: D000596:Amino Acids; D064267:Intrinsically Disordered Proteins
keywords: Intrinsically disordered proteins; Molecular recognition; Protean segments (ProSs); Protein interface; Protein-protein interactions; Relative accessible surface area (rASA)