Evolution of tRNA nucleotidyltransferases: a small deletion generated CC-adding enzymes.

ABSTRACT: CCA-adding enzymes are specialized polymerases that add a specific sequence (C-C-A) to tRNA 3' ends without requiring a nucleic acid template. In some organisms, CCA synthesis is accomplished by the collaboration of evolutionary closely related enzymes with partial activities (CC and A addition). These enzymes carry all known motifs of the catalytic core found in CCA-adding enzymes. Therefore, it is a mystery why these polymerases are restricted in their activity and do not synthesize a complete CCA terminus. Here, a region located outside of the conserved motifs was identified that is missing in CC-adding enzymes. When recombinantly introduced from a CCA-adding enzyme, the region restores full CCA-adding activity in the resulting chimera. Correspondingly, deleting the region in a CCA-addi

SUBMITTER: Neuenfeldt A 

PROVIDER: S-EPMC2430343 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature