Transient Secondary Structures as General Target-Binding Motifs in Intrinsically Disordered Proteins

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• Intrinsically disordered proteins (IDPs) lack stable 3D structures but are essential for biological functions.
• IDPs are implicated in critical diseases such as cancers, neurodegenerative disorders, and viral infections.
• Historically, IDPs were considered completely unstructured, even at the secondary structure level.

Purpose of the Study:

• To clarify the presence and significance of transient secondary structures in IDPs.
• To highlight the critical roles these structures play in IDP functions and target binding.
• To reconcile varying terminology used to describe transient secondary structures in the IDP field.

Main Methods:

• Literature review and synthesis of accumulated evidence over the last two decades.
• Analysis of diverse studies demonstrating transient secondary structures in IDPs.
• Examination of different expressions used to describe transient secondary structures in various contexts.

Main Results:

• IDPs are pre-populated with transient secondary structures in their target-free state.
• These transient structures are critical for the specific binding of IDPs to their targets.
• Evidence confirms that IDPs are not entirely devoid of secondary structure.

Conclusions:

• Transient secondary structures are a fundamental characteristic of IDPs, not an artifact.
• Understanding these structures is key to comprehending IDP functions and their roles in disease.
• Consistent terminology is needed to advance research in the dynamic field of intrinsically disordered proteins.