Organization of the ribosomal RNA genes in Mycoplasma hyopneumoniae: the 5S rRNA gene is separated from the 16S and 23S rRNA genes.

In order to study the organization of the ribosomal RNA genes of Mycoplasma hyopneumoniae the rRNA genes were cloned in phage vectors lambda EMBL3 and lambda EMBL4. By subcloning the restriction fragments into various plasmids and analysing the resulting clones by Southern and Northern blot hybridization, a restriction map of the rRNA genes was generated and the organization of the rRNA genes was determined. The results show that the genes for the 16S and 23S rRNAs are closely spaced and occur only once in the genome, whereas the 5S rRNA gene is separated from the other two genes by more than 4 kb.