The Labex Dynamo
2019 Trinquier et al.
tRNA maturation defects lead to inhibition of rRNA processing via synthesis of pppGpp.
Trinquier et al., 2019
Ribosomal RNAs and transfer RNAs universally require processing from longer primary transcripts to become functional for translation. Here we describe an unsuspected link between tRNA maturation and the 3’ processing of 16S rRNA, a key step in preparing the small ribosomal subunit for interaction with the Shine-Dalgarno sequence in prokaryotic translation initiation. We show that an accumulation of either 5’ or 3’ immature tRNAs triggers RelA-dependent production of the stringent response alarmone (p)ppGpp in the Gram-positive model organism Bacillus subtilis. The accumulation of (p)ppGpp and accompanying decrease in GTP levels specifically inhibit 16S rRNA 3’ maturation. We suggest that cells can exploit this mechanism to sense potential slow-downs in tRNA maturation and adjust rRNA processing accordingly to maintain the appropriate functional balance between these two major components of the translation apparatus.
Publish on : 06/05/2019