Cost-minimization of amino acid usage

Area of Science:

• Biochemistry
• Evolutionary Biology
• Genomics

Background:

• Organisms exhibit a negative correlation between amino acid usage frequency and biosynthetic cost.
• This suggests a biological imperative to minimize the energetic expenses associated with protein synthesis.

Purpose of the Study:

• To investigate the extent and mechanisms of biosynthetic cost minimization in protein synthesis across diverse organisms.
• To explore the relationship between amino acid cost, protein structure, expression levels, genome size, and evolutionary rates.

Main Methods:

• Comparative analysis of amino acid usage frequencies and their associated biosynthetic costs in free-living versus intracellular organisms.
• Correlation analysis between amino acid weight minimization (WM) and protein expression, size, evolutionary rate, and genome size.
• Examination of developmental rates in relation to WM in primates and rodents.

Main Results:

• Free-living organisms minimize heavy amino acid usage more than intracellular ones.
• Cost minimization is constrained by protein structure and function requirements.
• Protein weight minimization (WM) positively correlates with expression level and size, and negatively with evolutionary rate.
• WM decreases with genome size and positively correlates with developmental rates in mammals.

Conclusions:

• Biosynthetic cost minimization is a significant adaptive strategy influencing protein composition and organismal traits.
• The degree of cost minimization is modulated by ecological niche, metabolic strategies, and functional constraints.
• This principle offers a semi-mechanistic explanation for fitness differences at the molecular level.