Intrinsic protein disorder in complete genomes

Area of Science:

• Biochemistry
• Genomics
• Structural Biology

Background:

• Intrinsic protein disorder describes protein regions or entire proteins that lack a stable three-dimensional structure.
• Understanding the prevalence of protein disorder is crucial for comprehending protein function and evolution.

Purpose of the Study:

• To predict and quantify intrinsically disordered protein segments and whole proteins across diverse genomes.
• To compare the prevalence of protein disorder in bacteria, archaea, and eukaryotes.

Main Methods:

• Computational prediction of disordered protein segments and wholly disordered proteins.
• Analysis of protein sequences from 34 genomes (22 bacteria, 7 archaea, 5 eukaryotes).
• Categorization of disordered regions by length thresholds (>= 50, >= 40, >= 30 amino acids).

Main Results:

• Eukaryotes showed the highest percentages of disordered segments >= 50 amino acids (25-41%).
• Wholly disordered proteins were estimated at 1-8% in bacteria and 2-11% (average 7%) in archaea.
• Eukaryotes had estimates of wholly disordered proteins ranging from 3-17%.
• Disordered proteins included ribosomal proteins and those with known or unknown functions.

Conclusions:

• Intrinsic protein disorder is a common feature across bacteria, archaea, and eukaryotes.
• Eukaryotes appear to possess a higher proportion of native protein disorder compared to prokaryotes.
• Disordered proteins play diverse roles, including structural and functional capacities, across all domains of life.