Characterization of Aquifex aeolicus ribonuclease III and the reactivity epitopes of its pre-ribosomal RNA substrates.

ABSTRACT: Ribonuclease III cleaves double-stranded (ds) structures in bacterial RNAs and participates in diverse RNA maturation and decay pathways. Essential insight on the RNase III mechanism of dsRNA cleavage has been provided by crystallographic studies of the enzyme from the hyperthermophilic bacterium, Aquifex aeolicus. However, the biochemical properties of A. aeolicus (Aa)-RNase III and the reactivity epitopes of its substrates are not known. The catalytic activity of purified recombinant Aa-RNase III exhibits a temperature optimum of ∼70-85°C, with either Mg2+ or Mn2+ supporting efficient catalysis. Small hairpins based on the stem structures associated with the Aquifex 16S and 23S rRNA precursors are cleaved at sites that are consistent with production of the immediate precursors to the mat

SUBMITTER: Shi Z 

PROVIDER: S-EPMC3074117 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature