The wobble nucleotide-excising anticodon nuclease RloC is governed by the zinc-hook and DNA-dependent ATPase of its Rad50-like region.

The conserved bacterial anticodon nuclease (ACNase) RloC and its phage-excluding homolog PrrC comprise respective ABC-adenosine triphosphatase (ATPase) and ACNase N- and C-domains but differ in three key attributes. First, prrC is always linked to an ACNase silencing, DNA restriction-modification (R-M) locus while rloC rarely features such linkage. Second, RloC excises its substrate's wobble nucleotide, a lesion expected to impede damage reversal by phage transfer RNA (tRNA) repair enzymes that counteract the nick inflicted by PrrC.

RloC: a wobble nucleotide-excising and zinc-responsive bacterial tRNase.

The conserved bacterial protein RloC, a distant homologue of the tRNA(Lys) anticodon nuclease (ACNase) PrrC, is shown here to act as a wobble nucleotide-excising and Zn(++)-responsive tRNase. The more familiar PrrC is silenced by a genetically linked type I DNA restriction-modification (R-M) enzyme, activated by a phage anti-DNA restriction factor and counteracted by phage tRNA repair enzymes. RloC shares PrrC's ABC ATPase motifs and catalytic ACNase triad but features a distinct zinc-hook/coiled-coil insert that renders its ATPase domain similar to Rad50 and related DNA repair proteins.

[Gene silencing RNAi technology: possible application to therapy].

RNA interference (RNAi), i.e. gene silencing, or gene expression down-regulation is the process whereby a double-stranded RNA (dsRNA) induces the homology-dependent degradation of cognate messenger RNA (mRNA).