Iron mediated methylthiolation of tRNA as a regulator of operon expression in Escherichia coli.
AUTOR(ES)
Buck, M
RESUMO
E. coli growing in the presence of iron-binding proteins produced tRNAtrp and tRNAphe molecules containing i6A instead of ms2i6A adjacent to the anticodon. These undermodified tRNAs functioned less efficiently than the fully modified molecules when translating synthetic polynucleotides containing contiguous codons in an in vitro system, but did not limit the translation of MS2 RNA. We examined the possibility that the altered tRNAs with lowered translational efficiencies could relieve transcription termination at the trp and phe attenuators and lead to increased operon expression under iron restricted conditions. Using trpR mutants we found that there was indeed greater expression of the trp operon during iron restricted growth. This increase was attributable solely to the tRNA alteration induced by iron restriction.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=320637Documentos Relacionados
- Queuosine modification in tRNA and expression of the nitrate reductase in Escherichia coli.
- Sequential processing of precursor tRNA molecules in Escherichia coli.
- Accumulation of peptidyl tRNA is lethal to Escherichia coli.
- The nucleotide sequence of asparagine tRNA from Escherichia coli.
- Level of rRNA, not tRNA, synthesis controls transcription of rRNA and tRNA operons in Escherichia coli.