In Escherichia coli, ribosomal RNAs (16S, 23S and 5S) are co-transcribed in a highly regulated manner from seven genomically dispersed operons. Previous studies on the cellular effects of altered levels of two of these rRNAs (16S and 23S) have been useful in better understanding the regulation of rRNA expression. Furthering these studies, we have investigated the effect of 5S rRNA deficiencies ...

We have isolated and partially characterized an endonuclease involved in processing the 5' end of 16S rRNA of Escherichia coli. A mutant strain that is deficient in this enzyme accumulates a new precursor of 16S rRNA, named 16.3S rRNA. This rRNA has the 3' end of mature 16S rRNA but is about 60 nucleotides longer at the 5' end. In vitro, the enzyme preparation cleaves an RNA fragment of about 6...

It is difficult to distinguish between clinically significant slowly-growing, non-pigmented mycobacteria, notably to separate M. aviumand M. intracellulare from one another and from M. scrofulaceum strains. The purpose of this study was to evaluate the extent to which 16S rRNA sequencing could be used to highlight the taxonomic relationships of the mycobacterial strains, which are difficult to ...

Studies on earthworms using molecular markers are rare in Africa except a handful from South Africa. Reports on Libyodrilus violaceous,an earthworm found in West Africaare available including their metal tolerance and bioaccumulation capacity but their molecular characterization and ecotoxicology studies are scarce. In this study, triplicate L. violaceous specimens were collec...

Specific hybridization assays for intermediates in rRNA synthesis (pre-rRNA) may become useful for monitoring the growth activity of individual microbial species in complex natural systems. This possibility depends upon the assumption that rRNA processing in microbial cells continues after growth and pre-rRNA synthesis cease, resulting in drainage of the pre-rRNA pool. This is not the case in m...

Analysis of 16S rRNA gene sequences has become the primary method for determining prokaryotic phylogeny. Phylogeny is currently the basis for prokaryotic systematics. Therefore, the validity of 16S rRNA gene-based phylogenetic analyses is of fundamental importance for prokaryotic systematics. Discrepancies between 16S rRNA gene analyses and DNA-DNA hybridization and phenotypic analyses have bee...

The bacterial ribosome consists of three rRNA molecules and 57 proteins and plays a crucial role in translating mRNA-encoded information into proteins. Because of the ribosome's structural and mechanistic complexity, it is believed that each ribosomal component coevolves to maintain its function. Unlike 5S rRNA, 16S and 23S rRNAs appear to lack mutational robustness, because they form the struc...

Mycoplasmas are very small bacteria lacking cell walls that belong to various genera within the class Mollicutes, and also the smallest organisms that can live independently. They are able to cause serious and chronic disease because of some unique characteristics. Mycoplasma gallisepticum (MG) is an important avian pathogen causing significant economical losses within the poultry industry. The...

Phylogenetic relationships among species of the genus Ureaplasma were elucidated by analyzing 16S rRNA sequence information. The 16S rRNA genes of six strains of the mammalian Ureaplasma species were amplified by PCR and were sequenced directly by a primer walking method. The phylogenetic tree based on the nucleotide sequence of the 16S rRNA genes corresponded to the evolutionary history of the...