16S rRNA sequence indicates that plant-pathogenic mycoplasmalike organisms are evolutionarily distinct from animal mycoplasmas.

摘要: The plant-pathogenic mycoplasmalike organisms (MLOs) are so named because they lack cell walls. Many features that essential to a definitive classification remain uncharacterized, these have resisted attempts at in vitro culturing. To establish the taxonomic position of MLOs, DNA region containing 16S rRNA gene from representative MLOs has been cloned and sequenced. Sequence comparisons indicate related Mycoplasma capricolum two bacteria share their phylogenetic origin with Bacillus subtilis. low G + C content this its deduced secondary structure further support grouping. However, presence single tRNAIle spacer between 23S genes differentiates other representatives mycoplasmas, which indicates an early divergence evolution members class Mollicutes. certain characteristic oligonucleotides sequence may be closely acholeplasmas.