Paradigms of convergent evolution in enzymes

Area of Science:

• Biochemistry
• Structural Biology
• Evolutionary Biology

Background:

• Enzymes catalyzing identical reactions often exhibit distinct structures.
• Functional convergence, where unrelated proteins evolve similar functions, is a key area in evolutionary biochemistry.
• The Mechanism and Catalytic Site Atlas (M-CSA) provides a rich resource for studying enzyme function and evolution.

Purpose of the Study:

• To identify and analyze cases of functional convergence in enzymes.
• To investigate the evolutionary independence of structurally diverse enzymes catalyzing the same reaction.
• To characterize the sequence, structural, and mechanistic features underlying enzyme functional convergence.

Main Methods:

• Utilized the M-CSA database to identify 34 cases of enzymes with identical Enzyme Commission numbers but different CATH folds.
• Compared sequence, structure, active site geometry, cofactor usage, and catalytic mechanisms of these enzyme pairs.
• Integrated literature data with computational resources (M-CSA, PDBe, PDBsum) and custom software for analysis.

Main Results:

• Identified 34 instances of functional convergence among enzymes with distinct folds.
• Demonstrated that these enzymes evolved independently to perform the same chemical catalysis.
• Observed multiple distinct patterns of convergent functional evolution.

Conclusions:

• Functional convergence in enzymes is a recurring phenomenon with diverse evolutionary strategies.
• Accurate description of enzyme convergence requires integrated analysis of sequence, structure, active site, and mechanism.
• This study highlights the power of integrating structural databases and computational tools for evolutionary insights.