Number of natively unfolded proteins scales with genome size

TL;DR

This study demonstrates that the number of natively unfolded proteins in a genome scales with the total number of proteins, following a power law, which could shed light on their functional roles.

Contribution

The paper introduces a consensus scoring method to identify natively unfolded proteins across diverse genomes and reveals a scaling law relating their abundance to genome size.

Findings

Number of natively unfolded proteins correlates with total proteins in genomes.

Scaling law with exponent approximately 1.81 describes this relationship.

Method combines multiple indicators for accurate prediction across species.

Abstract

Natively unfolded proteins exist as an ensemble of flexible conformations lacking a well defined tertiary structure along a large portion of their polypeptide chain. Despite the absence of a stable configuration, they are involved in important cellular processes. In this work we used from three indicators of folding status, derived from the analysis of mean packing and mean contact energy of a protein sequence as well as from VSL2, a disorder predictor, and we combined them into a consensus score to identify natively unfolded proteins in several genomes from Archaea, Bacteria and Eukarya. We found a high correlation among the number of predicted natively unfolded proteins and the number of proteins in the genomes. More specifically, the number of natively unfolded proteins scaled with the number of proteins in the genomes, with exponent 1.81 +- 0.10. This scaling law may be important to understand the relation between the number of natively unfolded proteins and their roles in cellular processes.