Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

tRNA damage inflicted by the Escherichia coli anticodon nuclease PrrC (EcoPrrC) underlies an antiviral response to phage T4 infection. PrrC homologs are present in many bacterial proteomes, though their biological activities are uncharted. PrrCs consist of two domains: an N-terminal NTPase module related to the ABC family and a distinctive C-terminal ribonuclease module. In this article, we report that the expression of EcoPrrC in budding yeast is fungicidal, signifying that PrrC is toxic in a eukaryon in the absence of other bacterial or viral proteins. Whereas Streptococcus PrrC is also toxic in yeast, Neisseria and Xanthomonas PrrCs are not. Via analysis of the effects of 118 mutations on EcoPrrC toxicity in yeast, we identified 22 essential residues in the NTPase domain and 11 in the nuclease domain. Overexpressing PrrCs with mutations in the NTPase active site ameliorated the toxicity of wild-type EcoPrrC. Our findings support a model in which EcoPrrC toxicity is contingent on head-to-tail dimerization of the NTPase domains to form two composite NTP phosphohydrolase sites. Comparisons of EcoPrrC activity in a variety of yeast genetic backgrounds, and the rescuing effects of tRNA overexpression, implicate tRNA(Lys(UUU)) as a target of EcoPrrC toxicity in yeast.
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PMID:Determinants of eukaryal cell killing by the bacterial ribotoxin PrrC. 2085 93

Dynamic self-organisation far from equilibrium is a key concept towards building autonomously acting materials. Here, we report the coupling of an antagonistic enzymatic reaction of RNA polymerisation and degradation to the aggregation of micron sized DNA coated colloids into fractal structures. A transient colloidal aggregation process is controlled by competing reactions of RNA synthesis of linker strands by a RNA polymerase and their degradation by a ribonuclease. By limiting the energy supply (NTP) of the enzymatic reactions, colloidal clusters form and subsequently disintegrate without the need of external stimuli. Here, the autonomous colloidal aggregation and disintegration can be modulated in terms of lifetime and cluster size. By restricting the enzyme activity locally, a directed spatial propagation of a colloidal aggregation and disintegration front is realised.
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PMID:Transient self-organisation of DNA coated colloids directed by enzymatic reactions. 3108 64