Comparison of the conserved region in the dnaA gene from three mollicute species.

Polymerase chain reaction was carried out to amplify the conserved region (789 bp in the case of Mycoplasma capricolum) of the dnaA gene (1350 bp in the case of M. capricolum) of 15 representatives of the class Mollicutes using degenerate oligonucleotide primers. The dnaA gene fragments were amplified from M. mycoides subsp. capri, Spiroplasma apis and S. citri. The amino acid sequences deduced from the nucleotide sequences of the amplified fragments showed very low similarities to those of the corresponding regions of four walled bacteria. The values of similarity between any two of the three mollicute species were lower than those between any two of the four walled bacteria.