Partial sequences of the RNase P RNA gene (rnpB) were obtained from a number of hemoplasmas and other Mycoplasma species. Phylogenetic analysis of these sequences showed that all hemoplasmas were present within a single clade and were most closely related to Mycoplasma fastidiosum, similar to the results found with 16S rRNA gene phylogeny.

A mutant strain deficient in RNase T was isolated and used to study the role of this enzyme in Escherichia coli. Strains lacking as much as 70% of RNase T activity, alone or in combination with the absence of other RNases, display normal growth properties. However, in cca strains, which lack tRNA nucleotidyltransferase, RNase T-deficient derivatives accumulate lower levels of defective tRNA and...

conclusion in breast cancer after nac, the lesion t2 relaxation time was reduced in the responders, and this finding is potentially useful to assess the response to nac. results in 26 cases with nac, the mean lesion t2 relaxation time before nac was 81.34 ± 13.68 ms, compared with 64.50 ± 8.71 ms after nac. significant differences in the lesion t2 relaxation times existed between the pre- and p...

Sensitive profile searches and fold recognition were used to predict the structures of two yeast RNase P/MRP proteins. Rpp1p, which is one of the subunits common to eukaryotes and archaea, is predicted to adopt the seven-stranded TIM-barrel fold found in PHP phosphoesterases. Pop3p, initially thought to be one of the RNase P/MRP subunits unique to yeast, has been assigned the L7Ae/L30e fold. Th...

RNase P preparations from Escherichia coli can be separated into RNA and protein by chromatography, in buffers containing 7 M urea, on Sephadex G-200, DEAE-Sephadex, or CM-Sephadex columns. Neither RNA nor protein components alone exhibits any RNase activity. RNase P activity can be reconstituted by mixing separated RNA and protein components in buffer containing 7M urea followed by dialysis of...

Independently folded domains in RNAs frequently adopt identical tertiary structures regardless of whether they are in isolation or are part of larger RNA molecules. This is exemplified by the P15 domain in the RNA subunit (RPR) of the universally conserved endoribonuclease P, which is involved in the processing of tRNA precursors. One of its domains, encompassing the P15 loop, binds to the 3'-e...