Analysis of transcription and processing signals in the 5' regions of the two Mycoplasma capricolum rRNA operons.

The transcription and RNA processing signals of the rRNA operons (rrnA and rrnB) of Mycoplasma capricolum were analyzed by mapping the 5' ends of in vivo and in vitro synthesized RNAs. The results of both in vitro and in vivo analyses point to the rrnA operon being transcribed from two promoters (P1 and P2) into large precursor RNAs. Transcripts initiating at P1 contain two tRNAs, and probably 16 S, 23 S, and 5 S rRNAs, whereas the transcripts starting from P2 consist only of the three rRNAs.

Gene expression signals in Mycoplasma hyopneumoniae and Mycoplasma capricolum.

In Mycoplasma hyopneumoniae, the single genes for 16S and 23S rRNAs are clustered in one operon from which the 5S rRNA gene is separated by more than 4 kbp. This operon, gene 2413 and gene X from M. hyopneumoniae and the 5' ends of both rRNA operons from M.

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.

Analysis of transcription and processing signals of the 16S-23S rRNA operon of Mycoplasma hyopneumoniae.

The 16S and 23S rRNA genes of Mycoplasma hyopneumoniae are closely spaced in one operon. The two genes are separated by a spacer region of 500 bp which shows no sequence homology to bacterial tRNA genes. Within this operon seven 5' and five 3' ends of various rRNA species were mapped and the corresponding DNA was sequenced.