Abstract
SUMMARY: The phylogenetic relationships of three mycolateless wall type IV actinomycetes, Faenia rectivirgula, Pseudonocardia thermophila and Saccharopolyspora hirsuta, were examined using reverse transcriptase sequencing of 16S ribosomal RNA. The sequences generated were aligned and the level of sequence homology calculated. The homology values were then used to produce a phylogenetic tree and to estimate SAB values for the construction of a dendrogram. Both analyses show the three taxa to be closely related genera which form a distinct subdivision within the broader phylogenetic grouping defined by Mycobacterium, Dactylosporangium and their relatives.