A plasmodial alpha-tubulin cDNA from Physarum polycephalum. Nucleotide sequence and comparative analysis

Area of Science:

• Molecular Biology
• Cell Biology
• Evolutionary Biology

Background:

• Tubulin is a key protein in microtubule formation, essential for cell structure and function.
• Understanding tubulin diversity across species aids in comprehending microtubule evolution and specialization.

Purpose of the Study:

• To elucidate the nucleotide sequence of a plasmodial alpha-tubulin from Physarum polycephalum.
• To provide a foundation for correlating tubulin structure and function in this organism.

Main Methods:

• Nucleotide sequencing of a complementary DNA (cDNA) clone.
• Bioinformatic analysis and comparison of amino acid sequences with other known alpha-tubulins.

Main Results:

• The Physarum polycephalum alpha-tubulin cDNA sequence was determined, coding for most of the protein.
• Unique amino acid residues were identified in a specific region (298-307), with a conserved region near the C terminus (396-426).
• The sequence exhibited 70% homology to yeast and 83% homology to animal alpha-tubulins.

Conclusions:

• The findings provide insights into the molecular evolution of alpha-tubulin.
• A significant decrease in mutation rate during metazoan evolution suggests functional specialization of microtubules.
• This study establishes a basis for future research on Physarum polycephalum tubulin structure-function relationships.