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V S Artamonova

Publications and source records attributed to V S Artamonova.

10 recordsLinked to original sources
PubMed2006

[Uncontrolled genetic processes in artificial populations: proving the leading role of selection in evolution].

The review considers studies examining artificially maintained populations as models for understanding biological evolution. The key factors of gene pool evolution-random processes, interspecific hybridization, migration, mutation, and selection--are analyzed. We present evidence indicating that selection is the leading evolutionary factor that regulates the operation of other factors, directly or through genetic systems.

Animals↗
PubMed2004

[Hybridization between Atlantic salmon Salmo salar L. and brown trout S. trutta l. upon artificial propagation].

Samples of Salmo salar and S. trutta were examined in 12 Russian fish hatcheries. With protein markers, hybrids of the two species were found in three hatcheries of the Baltic Sea basin. Some fishes had a phenotype intermediate between the S. salar and S. trutta phenotypes by morphological traits, but did not differ genetically from one of the parental species. Possible consequences of hybridization and ways to prevent it are discussed.

Animals↗
PubMed2001

Non-canonical mechanism for translational control in bacteria: synthesis of ribosomal protein S1.

Translation initiation region (TIR) of the rpsA mRNA encoding ribosomal protein S1 is one of the most efficient in Escherichia coli despite the absence of a canonical Shine-Dalgarno-element. Its high efficiency is under strong negative autogenous control, a puzzling phenomenon as S1 has no strict sequence specificity. To define sequence and structural elements responsible for translational efficiency and autoregulation of the rpsA mRNA, a series of rpsA'-'lacZ chromosomal fusions bearing various mutations in the rpsA TIR was created and tested for beta-galactosidase activity in the absence and presence of excess S1. These in vivo results, as well as data obtained by in vitro techniques and phylogenetic comparison, allow us to propose a model for the structural and functional organization of the rpsA TIR specific for proteobacteria related to E.coli. According to the model, the high efficiency of translation initiation is provided by a specific fold of the rpsA leader forming a non-contiguous ribosome entry site, which is destroyed upon binding of free S1 when it acts as an autogenous repressor.

5' Untranslated Regions↗
PubMed2000

The last RNA-binding repeat of the Escherichia coli ribosomal protein S1 is specifically involved in autogenous control.

The ssyF29 mutation, originally selected as an extragenic suppressor of a protein export defect, has been mapped within the rpsA gene encoding ribosomal protein S1. Here, we examine the nature of this mutation and its effect on translation. Sequencing of the rpsA gene from the ssyF mutant has revealed that, due to an IS10R insertion, its product lacks the last 92 residues of the wild-type S1 protein corresponding to one of the four homologous repeats of the RNA-binding domain. To investigate how this truncation affects translation, we have created two series of Escherichia coli strains (rpsA(+) and ssyF) bearing various translation initiation regions (TIRs) fused to the chromosomal lacZ gene. Using a beta-galactosidase assay, we show that none of these TIRs differ in activity between ssyF and rpsA(+) cells, except for the rpsA TIR: the latter is stimulated threefold in ssyF cells, provided it retains at least ca. 90 nucleotides upstream of the start codon. Similarly, the activity of this TIR can be severely repressed in trans by excess S1, again provided it retains the same minimal upstream sequence. Thus, the ssyF stimulation requires the presence of the rpsA translational autogenous operator. As an interpretation, we propose that the ssyF mutation relieves the residual repression caused by normal supply of S1 (i.e., that it impairs autogenous control). Thus, the C-terminal repeat of the S1 RNA-binding domain appears to be required for autoregulation, but not for overall mRNA recognition.

Amino Acid Sequence↗
PubMed1998

[Regulation of synthesis of ribosomal protein L7-L12: role of intercistronic rplJL region as an enhancer of translation].

The ability of the Escherichia coli intercistronic rplJL region to initiate effectively the synthesis of the ribosomal protein L7/12, the only ribosomal component present in the ribosome in four copies rather than in one was studied in vivo and in vitro. It was shown that the structural determinants located upstream from the Shine-Dalgarno sequence and sharing structural motifs with the known E. coli translational enhancers are necessary for high activity of this region in translation initiation. These data indicate that mRNA-protein interactions through the ribosomal S1 protein play an important role in the formation of the initiation complex, and an enhancer region within the leader of the L7/12 mRNA serves as a target for this protein.

Bacterial Proteins↗
PubMed1996

[Mutation ssF29 in the gene for E. coli ribosomal protein S1, suppressing a defect in transmembrane protein transport results from insertion of the IS10R element].

The nature of the ssyF29 mutation causing the synthesis of a truncated form of the ribosomal protein S1 and its location in the rpsA gene were determined. The ssyF mutation was found to result from insertion of the IS10(R) element which causes the termination of translation of the corresponding mRNA at the first insertion nucleotide and the production of the S1 protein which is truncated at the C-terminus and composed of 464 amino acid residues (instead of 557 residues in the wild-type protein). The mutant rpsA gene (ssyF) encodes no additional amino acid residues as compared with the wild-type rpsA gene.

Base Sequence↗