The heteromeric Nanoarchaeum equitans splicing endonuclease cleaves noncanonical bulge-helix-bulge motifs of joined tRNA halves.

ABSTRACT: Among the tRNA population of the archaeal parasite Nanoarchaeum equitans are five species assembled from separate 5' and 3' tRNA halves and four species derived from tRNA precursors containing introns. In both groups an intervening sequence element must be removed during tRNA maturation. A bulge-helix-bulge (BHB) motif is the hallmark structure required by the archaeal splicing endonuclease for recognition and excision of all introns. BHB motifs are recognizable at the joining sites of all five noncontinuous tRNA species, although deviations from the canonical BHB motif are clearly present in at least two of them. Here, we show that the N. equitans splicing endonuclease cleaves tRNA precursors containing normal introns, as well as all five noncontinuous precursor tRNAs, at the predicted sp

SUBMITTER: Randau L 

PROVIDER: S-EPMC1312423 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature