Low Complexity Induces Structure in Protein Regions Predicted as Intrinsically Disordered.

Area of Science:

• Protein Biochemistry
• Structural Biology
• Bioinformatics

Background:

• Intrinsically disordered regions (IDRs) are crucial for protein interactions but often lack defined structures.
• Low complexity regions (LCRs), a subset of IDRs, are hypothesized to influence local protein structure.
• Understanding IDR structure is key to deciphering protein function and interactions.

Purpose of the Study:

• To investigate the role of LCRs in inducing local structure within intrinsically disordered regions (IDRs).
• To analyze the structural propensities of different types of LCRs (polyX, polyXY) within IDRs.
• To propose bioinformatics methods for studying IDR structural behavior.

Main Methods:

• Prediction of IDRs across the human proteome.
• Analysis of protein structures from the Protein Data Bank (PDB) for identified IDRs and LCRs.
• Classification and structural characterization of simple LCRs (polyX, polyXY) within IDRs.

Main Results:

• LCRs, particularly polyX (61.8%) and polyXY (50.5%), showed higher PDB structural assignment rates than surrounding IDRs (39.7%).
• Poly(E) (polyEK) regions were found to induce helical conformations.
• Other frequent LCRs predominantly adopted coil structures.

Conclusions:

• Low complexity regions within intrinsically disordered regions can induce local structural conformations.
• Specific LCRs, like poly(E), promote helical structures, while others favor coil formations.
• Bioinformatics approaches can effectively elucidate the structural roles of LCRs in IDRs, contributing to understanding protein function.