Processing of the alaW alaX operon encoding the Ala2 tRNAs in Escherichia coli requires both RNase E and RNase P.
Mol Microbiol
; 118(6): 698-715, 2022 12.
Article
em En
| MEDLINE
| ID: mdl-36268779
ABSTRACT
The alaW alaX operon encodes the Ala2 tRNAs, one of the two alanine tRNA isotypes in Escherichia coli. Our previous RNA-seq study showed that alaW alaX dicistronic RNA levels increased significantly in the absence of both RNase P and poly(A) polymerase I (PAP I), suggesting a role of polyadenylation in its stability. In this report, we show that RNase E initiates the processing of the primary alaW alaX precursor RNA by removing the Rho-independent transcription terminator, which appears to be the rate limiting step in the separation and maturation of the Ala2 pre-tRNAs by RNase P. Failure to separate the alaW and alaX pre-tRNAs by RNase P leads to poly(A)-mediated degradation of the dicistronic RNAs by polynucleotide phosphorylase (PNPase) and RNase R. Surprisingly, the thermosensitive RNase E encoded by the rne-1 allele is highly efficient in removing the terminator (>99%) at the nonpermissive temperature suggesting a significant caveat in experiments using this allele. Together, our data present a comprehensive picture of the Ala2 tRNA processing pathway and demonstrate that unprocessed RNase P substrates are degraded via a poly(A) mediated decay pathway.
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1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Escherichia coli
/
Ribonuclease P
Idioma:
En
Revista:
Mol Microbiol
Ano de publicação:
2022
Tipo de documento:
Article