UNUSUAL ORGANIZATION OF THE 23S RIBOSOMAL-RNA GENES IN THE RHIZOBIACEAE

The presence of intervening sequences (IVSs) in the 23S rRNA genes of rhizobia and the phenomenon of fragmentation of their matured 23S-like rRNA molecules are analysed. A novel IVS-IVS II, in the 23S rRNA gene of several rhizobial strains is described, which is located approxima tely at position 540 bp (E. coli numeration). In contrast to the recen tly published IVS I occurring at position 130 of the gene, which was s hown to be a common feature for all representatives of the family Rhiz obiaceae, the IVS II was found only in a limited number of strains. (C ) 1997 Elsevier Science Ltd.