Gene/Protein
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Enzyme
Compound
Pivot Concepts:
Gene/Protein
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Target Concepts:
Gene/Protein
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Query: EC:3.1.26.5 (
RNase P
)
1,348
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We have determined that 10Sa RNA (one of the small stable RNAs found in Escherichia coli) has an interesting structural feature: the 5' end and the 3' end of 10Sa RNA can be arranged in a structure that is equivalent to a half-molecule (acceptor stem and TFC stem-loop) of alanine tRNA of E. coli. Primer-extension analysis of 10Sa RNA extracted from a bacterial mutant with temperature-sensitive
RNase P
function revealed that the precursor to 10Sa RNA (pre-10Sa RNA) is folded into a pre-tRNA-like structure in vivo such that it can be cleaved by
RNase P
to generate the 5' end of the mature 10Sa RNA. The purified 10Sa RNA can be charged with alanine in vitro. Disruption of the gene encoding 10Sa RNA (ssrA) caused a reduction in the rate of cell growth, which was especially apparent at 45 degrees C, and a reduction in motility on semisolid agar. These phenotypic characteristics of the deletion strain (delta ssrA) allowed us to investigate the effects of some mutations in 10Sa RNA in vivo, although the exact function of 10Sa RNA still remains unclear. When the G.U pair (G3.U357) in 10Sa RNA, which may be equivalent to the determinant G.U pair of alanine tRNA, was changed to a G.A or G.C pair, the ability to complement the phenotypic mutations of the delta ssrA strain was lost. Furthermore, this inability to complement the mutant phenotypes that was caused by the substitution of the determinant bases by a G.A pair could be overcome by the introduction of a gene encoding
alanyl-tRNA synthetase
(alaS) on a multicopy plasmid. The evidence suggests that the proposed structural features of 10Sa RNA are indeed manifested in vivo.
...
PMID:A tRNA-like structure is present in 10Sa RNA, a small stable RNA from Escherichia coli. 752 73
It has been postulated that a highly reduced form of transfer messenger RNA (tmRNA), a bacterial molecule involved in the rescue of stalled ribosomes during translation, is expressed in the mitochondrion of the jakobid Reclinomonas americana. Here we show that genes encoding both one-piece and two-piece tmRNAs are present in six different jakobid mitochondrial DNAs. Mitochondrial tmRNAs have retained the highly conserved tRNA(Ala)-like domain, but they apparently lack the mRNA-like region present in all bacterial tmRNAs. Comparative analysis of jakobid mitochondrial genomes shows that a potential mRNA-like region in R. americana (orf64) is located at distant genomic positions in other jakobids. Our results strongly suggest that orf64 is a tatA homolog. Through Northern hybridization we confirm the postulated reduced size of both a one-piece tmRNA in Jakoba libera and a two-piece tmRNA in Seculamonas ecuadoriensis. The J. libera tmRNA is post-transcriptionally modified by addition of a 3' CCA tail, processed in vitro by
RNase P
RNA, and specifically charged with alanine in vitro by
alanyl-tRNA synthetase
. Our results strongly support the functionality of these reduced mitochondrial tmRNAs.
...
PMID:Loss of the mRNA-like region in mitochondrial tmRNAs of jakobids. 1503 63