Secondary structure of the autoregulatory mRNA binding site of ribosomal protein L1

Kearney, Kevin R.; Nomura, Masayasu

doi:10.1007/bf00337759

Cited by 28 publications

(15 citation statements)

References 17 publications

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“…A secondary-structure model, predicted by computer and supported by enzymatic probing, showed resemblance of this region to the Li binding site on 23S rRNA (12). In another example, however, i.e., the autogenous regulation of the (x operon by ribosomal protein S4, no resemblance could be found between the S4 target site on the mRNA (at a region 5' to the initiation codon of the S13 cistron [6]) and the S4 binding site on the 16S rRNA (7).…”

Section: Methodsmentioning

confidence: 80%

Autogenous regulation of the Escherichia coli ksgA gene at the level of translation

1989

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Various plasmids that contain the Escherichia coli ksgA gene, which encodes a 16S rRNA adenosine dimethyltransferase (methylase), were constructed. In one of these plasmids, the DNA encoding the N-terminal part of the methylase was fused to the lacZ gene, and in another construct, the ksgA gene contained a deletion which resulted in a truncated version of the methylase. When a cell contained one plasmid directing the synthesis of the intact, active methylase and another plasmid encoding the methylase-4-galactosidase protein, production of the latter product became strongly reduced. Likewise, synthesis of the truncated version of the methylase was diminished when the cell at the same time contained a plasmid producing the complete enzyme. These results were partly substantiated by in vitro experiments with a coupled transcription-translation assay system. By using a recently developed gel electrophoresis system for measuring protein-nucleic acid interactions, a specific binding of the ksgA methylase with its own mRNA could be established. Our results demonstrate that the expression of the ksgA gene can be, at least partly, autogenously controlled at the level of translation.

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Section: Methodsmentioning

confidence: 80%

Autogenous regulation of the Escherichia coli ksgA gene at the level of translation

1989

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“…The regulatory target site on the mRNA, which is highly similar to the binding site on the 23S rRNA, was localized to the untranslated leader sequence of the Lll-Li mRNA, and has been studied in detail (28,61). The a operon of E. coli is divided into two distinct regulatory units.…”

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confidence: 99%

Autogenous translational regulation of the ribosomal MvaL1 operon in the archaebacterium Methanococcus vannielii

et al. 1994

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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 MvaLl, MvaL10, and MvaL12, encoded by the MvaLl operon of Methanococcus vannielii, a methanogenic archaebacterium. MvaLl, the homolog of the regulatory protein Li encoded by the Lll operon of Escherichia coli, was shown to be an autoregulator of the MvaLl operon. As in E. coli, regulation takes place at the level of translation. The target site for repression by MvaLl was localized by site-directed mutagenesis to a region within the coding sequence of the MvaLl gene commencing about 30 bases downstream of the ATG initiation codon. The MvaLl binding site on the mRNA exhibits similarity in both primary sequence and secondary structure to the Li regulatory target site ofE. coli and to the putative binding site for MvaLl on the 23S rRNA. In contrast to other regulatory systems, the putative MvaLl 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.Ribosomes from different species of archaebacteria have been investigated extensively in the past, largely because they have proven to be excellent phylogenetic probes to study molecular evolution (38,39). A large amount of data is now available on ribosomal (r) proteins of archaebacteria. On the whole, the primary structures of archaebacterial r proteins are more related to their eukaryotic than to their eubacterial counterparts. In contrast, the genes for r proteins are arranged in operons as in eubacteria; even the order of the genes within the operons is similar to that found in eubacteria. Methanococcus vannielii, a methanogenic archaebacterium, contains more than 60 r proteins (49), a value intermediate between that found in eubacteria and that in eukaryotes. In general, the Methanococcus r proteins have higher molecular masses than their eubacterial homologs. As in Escherichia coli, the archaebacterial r protein equivalent to L12 is present in four copies per ribosome (7). In M. vannielii, three r protein operons have been characterized in detail: two transcription units corresponding to the E. coli spectinomycin and streptomycin operon (1,35), and the MvaLl operon (3). The MvaLl operon encodes the r proteins MvaLi, MvaL10, and MvaL12 (Fig. 1) rium cutirubrum (50) and in the sulfur-dependent thermophilic archaebacterium Sulfolobus solfataricus (51), the equivalent r protein genes are clustered in the same order as in E. coli. The regulation of the expression of many r protein operons has been investigated in E. coli (27,43). In most cases, a translational feedback regulation exists, in which certain r proteins act as autogenous repressors, controlling the expression of the operon in which they...

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“…However, little is known about the mechanism by which translation is controlled or about the structure of the mRNA region involved in the regulatory protein recognition. In bacteria, secondary structure information has been provided for some of the ribosomal protein operator regions by computer predictions and by nuclease probing experiments (6)(7)(8).In the present work, we have investigated in detail the conformation of a mRNA fragment obtained by in vitro transcription, containing the translational operator of the threonine:tRNAThr ligase (EC 6.1.1.3). Previous work has clearly shown that the expression of the threonine:tRNAThr ligase gene (thrS) is negatively autoregulated at the translational level (9, 10).…”

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confidence: 99%

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confidence: 99%

Messenger RNA structure and gene regulation at the translational level in Escherichia coli: the case of threonine:tRNAThr ligase.

Moine

Romby

Springer

et al. 1988

Proc. Natl. Acad. Sci. U.S.A.

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Previous work showed that the expression of the Escherichia coli threonine:tRNAThr ligase (EC 6.1.1.3)-encoding gene (thrS) is negatively autoregulated at the translational level and that a region called the operator that is located between 10 and 50 base pairs upstream of the translation initiation codon of the thrS gene is directly involved in that control. The conformation of an in vitro synthesized RNA fragment extending over the thrS regulatory region has been investigated using chemical and enzymatic probes. This study shows that the RNA folds into four well-defined secondarystructure domains, one of them displaying structural similarities to the anticodon arm of tRNAThF. The conformation of three constitutive mutants containing single base changes in the operator region leading to the loss of the regulatory control was also investigated. The replacement of a base in the anticodonlike loop does not induce any conformational change, suggesting that the residue concerned is directly involved in the regulatory process. However, single mutations in or close to the anticodon-like stem result in a partial or complete reorganization of the structure of the operator region. These rearrangements should affect the binding of the ligase to the operator, leading to loss of the regulatory process.In addition to the classical transcriptional regulation of gene expression, an increasing number of phage, bacterial, and eukaryotic genes appears to be regulated at the level of translation (1-5). In many cases the control has been characterized as a negative autoregulation involving a repressor protein acting at specific control sites of the target genes or operons. However, little is known about the mechanism by which translation is controlled or about the structure of the mRNA region involved in the regulatory protein recognition. In bacteria, secondary structure information has been provided for some of the ribosomal protein operator regions by computer predictions and by nuclease probing experiments (6)(7)(8).In the present work, we have investigated in detail the conformation of a mRNA fragment obtained by in vitro transcription, containing the translational operator of the threonine:tRNAThr ligase (EC 6.1.1.3). Previous work has clearly shown that the expression of the threonine:tRNAThr ligase gene (thrS) is negatively autoregulated at the translational level (9, 10). By a genetic approach, Springer et al. (11) have defined the thrS translational operator as a region located between 10 and 50 nucleotides (nt) upstream of the translational initiation codon and more than 100 bases downstream of the transcription initiation site. Our results show that the region located upstream to the initiation codon is organized in four distinct structural domains. One of these domains, which corresponds to the genetically defined operator, shares several primary-and secondary-structure features with the anticodon arm of some tRNAThr isoaccepting species. Similar studies were conducted on three mutant mRNAs containing single ba...

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Secondary structure of the autoregulatory mRNA binding site of ribosomal protein L1

Cited by 28 publications

References 17 publications

Autogenous regulation of the Escherichia coli ksgA gene at the level of translation

Autogenous regulation of the Escherichia coli ksgA gene at the level of translation

Autogenous translational regulation of the ribosomal MvaL1 operon in the archaebacterium Methanococcus vannielii

Messenger RNA structure and gene regulation at the translational level in Escherichia coli: the case of threonine:tRNAThr ligase.

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