Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Stability of RNA was tested in strains of Escherichia coli carrying single, double, or triple mutations in the RNA processing enzymes RNase III, RNase E and RNase P. Tests were carried out for total pulse labeled RNA, beta-galactosidase mRNA and for the decay of preexisting RNA during carbon starvation. Decay of RNA was measured at permissive and nonpermissive temperatures, and in no case were significant differences between mutants and non-mutant strains found. Therefore, we conclude that the three processing enzymes; RNase III, E and P do not contribute significantly to turnover of RNA IN Escherichia coli.
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PMID:Decay of RNA in RNA processing mutants of Escherichia coli. 615 28

The promoter of the rnpB gene (encoding the RNA component of Escherichia coli RNase P) shares a consensus discriminator sequence, located between the -10 hexamer sequence and the transcription start site, with other promoters whose activities are repressed upon stringent condition. Under stringent conditions induced by seryl-tRNA starvation the transcription of the rnpB gene was repressed in wild type E. coli but not in a relaxed strain carrying a relA- mutation. Site-directed mutagenesis was carried out to examine sequences of the rnpB promoter necessary for stringent control. The results indicate that the discriminator region is responsible for the transcription repression of the rnpB gene during the stringent response and that both the content and position of GC pairs in the region determine the strength of negative stringent signals.
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PMID:Escherichia coli rnpB promoter mutants altered in stringent response. 901 66

G350 of Escherichia coli RNase P RNA is a highly conserved residue among all bacteria and lies near the known magnesium binding site for the RNase P ribozyme, helix P4. Mutations at G350 have a dramatic effect on substrate cleavage activity for both RNA alone and holoenzyme; the G350C mutation has the most severe phenotype. The G350C mutation also inhibits growth of cells that express the mutant RNA in vivo under conditions of magnesium starvation. The results suggest that G350 contributes to Mg(2+) binding at helix P4 of RNase P RNA.
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PMID:G350 of Escherichia coli RNase P RNA contributes to Mg2+ binding near the active site of the enzyme. 1223 79