Intrinsically disordered proteins

<p>In <a href="/facts/Molecular_biology/YgqU35ub">molecular biology</a>, an intrinsically disordered protein (IDP) is a <a href="/facts/Protein/Jxmagu3E">protein</a> that lacks a fixed or ordered <a href="/facts/Protein_tertiary_structure/1QJVj1V1">three-dimensional structure</a>, typically in the absence of its <a href="/facts/Macromolecular/039ULSLg">macromolecular</a> interaction partners, such as other proteins or <a href="/facts/RNA/HxPeNfNj">RNA</a>. IDPs range from fully unstructured to partially structured and include <a href="/facts/Random_coil/pwVmGGUN">random coil</a>, <a href="/facts/Molten_globule/MBJG2wCq">molten globule</a>-like <a href="/facts/Protein_aggregation/94Ad1VqG">aggregates</a>, or flexible linkers in large multi-<a href="/facts/Protein_domain/oUpFcSsl">domain</a> proteins. They are sometimes considered as a separate class of proteins along with <a href="/facts/Globular_protein/PBlAMbBP">globular</a>, <a href="/facts/Fibrous_protein/v4zn56X8">fibrous</a> and <a href="/facts/Membrane_protein/FboTeM8Q">membrane proteins</a>.
</p><p>IDPs are a very large and functionally important class of proteins. They are most numerous in <a href="/facts/Eukaryote/SkwyPLMA">eukaryotes</a>, with an estimated 30-40% of residues in the eukaryotic proteome located in disordered regions. Disorder is present in around 70% of proteins, either in the form of disordered tails or flexible linkers. Proteins can also be entirely disordered and lack a defined <a href="/facts/Protein_secondary_structure/MMgXXbQ2">secondary</a> and/or <a href="/facts/Protein_tertiary_structure/1QJVj1V1">tertiary structure</a>. Their discovery has disproved the idea that three-dimensional structures of proteins must be fixed to accomplish their <a href="/facts/Biological_function/a5hLtnS7">biological functions</a>. For example, IDPs have been identified to participate in weak <a href="/facts/Multivalent/aQW0V4VH">multivalent</a> interactions that are highly cooperative and dynamic, lending them importance in <a href="/facts/Gene_expression/alCPohLR">DNA regulation</a> and in <a href="/facts/Cell_signaling/6oYAVP9I">cell signaling</a>. Many IDPs can also adopt a fixed three-dimensional structure after binding to other macromolecules. Overall, IDPs are different from structured proteins in many ways and tend to have distinctive function, structure, <a href="/facts/Protein_primary_structure/QNBoERdu">sequence</a>, interactions, evolution and regulation.
</p>

Intrinsically disordered proteins open-in-new

Intrinsically disordered proteins