Isolation and characterization of the single β-tubulin gene in Phytophthora cinnamomi

To initiate studies on the regulation of tubulin expression and microtubule organization in the phytopathogenic Oomycete, Phytophthora cinnamomi, a gene encoding beta-tubulin was cloned and sequenced. The gene has no introns and encodes a protein of 445 amino acids. Genomic Southern blots indicate a single copy of the beta-tubulin gene in the P. cinnamomi genome. Comparison of the P. cinnamomi beta-tubulin gene sequence with beta-tubulin genes from a range of fungi, algae and protists supports the hypothesis that the Oomycetes are more closely related to the algae and protists than they are to the higher fungi.