Autogenous translational regulation of the ribosomal MvaL1 operon in the archaebacterium Methanococcus vannielii.
AUTOR(ES)
Hanner, M
RESUMO
The mechanisms for regulation of ribosomal gene expression have been characterized in eukaryotes and eubacteria, but not yet in archaebacteria. We have studied the regulation of the synthesis of ribosomal proteins MvaL1, MvaL10, and MvaL12, encoded by the MvaL1 operon of Methanococcus vannielii, a methanogenic archaebacterium. MvaL1, the homolog of the regulatory protein L1 encoded by the L11 operon of Escherichia coli, was shown to be an autoregulator of the MvaL1 operon. As in E. coli, regulation takes place at the level of translation. The target site for repression by MvaL1 was localized by site-directed mutagenesis to a region within the coding sequence of the MvaL1 gene commencing about 30 bases downstream of the ATG initiation codon. The MvaL1 binding site on the mRNA exhibits similarity in both primary sequence and secondary structure to the L1 regulatory target site of E. coli and to the putative binding site for MvaL1 on the 23S rRNA. In contrast to other regulatory systems, the putative MvaL1 binding site is located in a sequence of the mRNA which is not in direct contact with the ribosome as part of the initiation complex. Furthermore, the untranslated leader sequence is not involved in the regulation. Therefore, we suggest that a novel mechanism of translational feedback regulation exists in M. vannielii.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=205064Documentos Relacionados
- Structure, organization and evolution of the L1 equivalent ribosomal protein gene of the archaebacterium Methanococcus vannielii.
- Polyadenylated, noncapped RNA from the archaebacterium Methanococcus vannielii.
- TTG serves as an initiation codon for the ribosomal protein MvaS7 from the archaeon Methanococcus vannielii.
- Purine metabolism in Methanococcus vannielii.
- RNA polymerase-binding and transcription initiation sites upstream of the methyl reductase operon of Methanococcus vannielii.