Coq3p relevant residues for protein activity and stability

Area of Science:

• Biochemistry
• Molecular Biology
• Yeast Genetics

Background:

• Coenzyme Q (CoQ) is vital for cellular respiration, transferring electrons in mitochondria.
• CoQ biosynthesis in Saccharomyces cerevisiae involves fourteen proteins, forming the CoQ synthome.
• The O-methyltransferase Coq3p is essential for CoQ maturation, requiring S-adenosylmethionine.

Purpose of the Study:

• To identify functional residues of the Coq3p enzyme using molecular modeling and mutagenesis.
• To understand the role of conserved and coevolved residues in Coq3p function and stability.
• To investigate structural differences in Coq3p between S. cerevisiae and lipid-producing yeast.

Main Methods:

• Ab initio molecular modeling to predict protein structure and function.
• Site-directed mutagenesis to alter specific amino acid residues in Coq3p.
• Multiple sequence alignment to compare Coq3p across different yeast species.

Main Results:

• Identified critical functional residues in Coq3p essential for its catalytic activity and CoQ biosynthesis.
• Demonstrated the importance of conserved and coevolved residues for respiratory growth and CoQ synthome stability.
• Discovered a poorly conserved 45-amino acid insertion in S. cerevisiae Coq3p compared to oleaginous yeast.

Conclusions:

• Coq3p's structural determinants for biological and catalytic functions have been elucidated.
• Understanding Coq3p variations can inform the engineering of lipid-producing yeast for biotechnological applications.