Molecular markers of serine protease evolution

Area of Science:

• Biochemistry
• Molecular Biology
• Evolutionary Biology

Background:

• Serine proteases are enzymes with critical roles, and their evolutionary history is complex.
• Understanding their evolution requires analyzing conserved residues within their catalytic apparatus.

Purpose of the Study:

• To trace the evolutionary history and phylogenetic relationships of serine proteases.
• To identify markers for tracking changes in the active site and supporting structures.
• To investigate the evolutionary mechanisms shaping serine protease families.

Main Methods:

• Analysis of conserved amino acids and serine codon usage in catalytic sites.
• Phylogenetic categorization of chymotrypsin-like, subtilisin-like, and alpha/beta-hydrolase fold clans.
• Examination of evolutionary markers in newly sequenced genes with multiple protease domains.

Main Results:

• Conserved residues act as markers for serine protease evolution, categorizing them into distinct phylogenetic lineages.
• Three unrelated serine protease clans (chymotrypsin-like, subtilisin-like, alpha/beta-hydrolase) share a common evolutionary theme: the catalytic tetrad.
• Analysis suggests domain duplication followed by gene splitting as a mechanism for mutating conserved markers.

Conclusions:

• Conserved amino acid markers effectively delineate serine protease evolutionary lineages and their relative ages.
• The catalytic tetrad is a convergent evolutionary feature across unrelated serine protease clans.
• Domain duplication and gene splitting provide a plausible genetic mechanism for evolutionary changes in serine proteases.