Structure and organization of the rrnD operon of 'Brevibacterium lactofermentum': analysis of the 16S rRNA gene

E. Amador, J. M. Castro, A. Correia, J. F. Martin
1999 Microbiology  
Five rRNA operons (rrn) were found by hybridization in the genome of ' Brevibacterium lacto fermenturn ' ATCC 13869 and Corynebacterium glutamicum ATCC 13032. 'B. lactofermentum' DSM 20412 differed from the other corynebacteria tested in showing six hybridizing BamHI bands. Two of the rrn operons (rrnD and rrnn were located in a single cosmid. Sequencing of the rrnD operon showed that it contains a complete 165 rRNA-23s RNA-5S rRNA gene cluster. Phylogenetic studies using the complete 165 rRNA
more » ... complete 165 rRNA sequence showed that 'B. lactofermentum ' is closely related to several species of the genus Corynebacterium but only distantly related to the type species Brevibacterium linens and the authors suggest that it should be reclassified as Corynebacterium lactofermenturn. The 5' end of mature 16s rRNA was identified by primer extension. Sequence elements similar to those of mycobacteria implicated in transcription antitermination (Boxes A, B, C) and in processing of the pre-rRNA to 16s rRNA were identified. An open reading frame encoding an rpoD-like sigma factor (named SigC) different from the previously reported SigA and SigB proteins was found upstream of rrnD in the opposite orientation. Both rpoD and sigC seem to be expressed from a bidirectional promoter region.
doi:10.1099/13500872-145-4-915 pmid:10220171 fatcat:6b2zr3ezlvfabixozgfhhgylk4