Transcription analysis of two disparate rRNA operons in the halophilic archaeon Haloarcula marismortui.

ABSTRACT: The genome of the halophilic archaeon Haloarcula marismortui contains two rRNA operons designated rrnA and rrnB. Genomic clones of the two operons and their flanking regions have been sequenced, and primary transcripts and processing intermediates derived from each operon have been characterized. The 16S, 23S, and 5S genes from the two operons were found to differ at 74 of 1,472 positions, 39 of 2,922 positions, and 2 of 122 positions, respectively. This degree of sequence divergence for multicopy (paralogous) rRNA genes was 10- to 50-fold or more higher than anticipated. The two operons exhibit other profound differences that include (i) the presence in rrnA and the absence in rrnB of tRNAAla and tRNACys genes in the intergenic and distal regions, respectively, (ii) divergent 5' flanking

SUBMITTER: Dennis PP 

PROVIDER: S-EPMC107503 | biostudies-literature | 1998 Sep

REPOSITORIES: biostudies-literature